diff --git a/.gitignore b/.gitignore
index fa5c6c6fcd..0f9259440e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,3 +37,4 @@ CMakeLists.txt.user
 CMakeUserPresets.json
 testing/data/tmp*
 testing/data/*-tmp-*
+testing/data/.mrtrix_testing.lock
diff --git a/cmake/BashTests.cmake b/cmake/BashTests.cmake
index 573c801a01..5902bf52f8 100644
--- a/cmake/BashTests.cmake
+++ b/cmake/BashTests.cmake
@@ -6,11 +6,12 @@ function(add_bash_test)
         message(FATAL_ERROR "bash not found")
     endif()
 
+    set(options NO_FILESYSTEM_LOCK)
     set(singleValueArgs FILE_PATH PREFIX WORKING_DIRECTORY ENVIRONMENT)
     set(multiValueArgs EXEC_DIRECTORIES LABELS)
     cmake_parse_arguments(
         ARG
-        ""
+        "${options}"
         "${singleValueArgs}"
         "${multiValueArgs}"
         ${ARGN}
@@ -34,22 +35,50 @@ function(add_bash_test)
 
     string(REPLACE ";" ":" exec_directories "${exec_directories}")
 
-    set(cleanup_cmd "rm -rf ${working_directory}/tmp* ${working_directory}/*-tmp-*")
+    # Bash tests sharing a working directory write, overwrite and delete temporary
+    # filesystem content prefixed "tmp"; running two such tests concurrently lets
+    # one test's cleanup clobber another's in-flight temporaries.
+    # Tests are serialised per working directory by two complementary mechanisms:
+    #   - the CTest RESOURCE_LOCK property (within a single ctest invocation), and
+    #   - a filesystem-level lock in RunTest.cmake (across invocations/instances).
+    # A test that the developer certifies never writes to the filesystem can opt
+    # out of both via NO_FILESYSTEM_LOCK, leaving it free to run in parallel.
+    set(run_test_args
+        -D BASH=${BASH}
+        -D FILE_PATH=${file_path}
+        -D WORKING_DIRECTORY=${working_directory}
+    )
+    if(NOT ARG_NO_FILESYSTEM_LOCK)
+        # The lock file lives inside the guarded directory itself, so every test
+        # sharing that directory (including across build trees that share it)
+        # agrees on the same lock; its fixed name avoids the "tmp" cleanup glob.
+        set(cleanup_cmd "rm -rf ${working_directory}/tmp* ${working_directory}/*-tmp-*")
+        set(lock_file "${working_directory}/.mrtrix_testing.lock")
+        list(APPEND run_test_args
+            -D CLEANUP_CMD=${cleanup_cmd}
+            -D LOCKFILE=${lock_file}
+        )
+    endif()
 
     add_test(
         NAME ${test_name}
         COMMAND
             ${CMAKE_COMMAND}
-            -D BASH=${BASH}
-            -D FILE_PATH=${file_path}
-            -D CLEANUP_CMD=${cleanup_cmd}
-            -D WORKING_DIRECTORY=${working_directory}
+            ${run_test_args}
             -P ${PROJECT_SOURCE_DIR}/cmake/RunTest.cmake
     )
     set_tests_properties(${test_name}
         PROPERTIES
         ENVIRONMENT "PATH=${exec_directories};${environment}"
     )
+    if(NOT ARG_NO_FILESYSTEM_LOCK)
+        # One resource per unique working directory: tests holding the same lock
+        # string are never scheduled concurrently by a single ctest invocation.
+        set_tests_properties(${test_name}
+            PROPERTIES
+            RESOURCE_LOCK "${working_directory}"
+        )
+    endif()
     if(labels)
         set_tests_properties(${test_name} PROPERTIES LABELS "${labels}")
     endif()
diff --git a/cmake/RunTest.cmake b/cmake/RunTest.cmake
index 2157452bf0..3cebdbdad5 100644
--- a/cmake/RunTest.cmake
+++ b/cmake/RunTest.cmake
@@ -1,15 +1,30 @@
 # This script can be invoked by calling ${CMAKE_COMMAND} -P <script_name>.cmake
 # Runs a bash test described by the FILE_PATH variable
 # The test is run in the WORKING_DIRECTORY directory
-# The CLEANUP_CMD command is run after the test is finished
+# The CLEANUP_CMD command, if provided, is run after the test is finished
+# If LOCKFILE is provided, an exclusive filesystem-level lock is held across both
+# the test and its cleanup, serialising tests that share a working directory even
+# across separate ctest invocations or instances. The lock is released
+# automatically when this process exits (including on crash), so a failed test
+# cannot deadlock subsequent runs.
+
+if(DEFINED LOCKFILE AND NOT LOCKFILE STREQUAL "")
+    # file(LOCK) yields "0" on success or an error message otherwise.
+    file(LOCK ${LOCKFILE} GUARD PROCESS RESULT_VARIABLE lock_result)
+    if(NOT lock_result STREQUAL "0")
+        message(FATAL_ERROR "Failed to acquire test lock ${LOCKFILE}: ${lock_result}")
+    endif()
+endif()
 
 execute_process(COMMAND ${BASH} -e ${FILE_PATH}
     RESULT_VARIABLE test_result_${FILE_PATH}
     WORKING_DIRECTORY ${WORKING_DIRECTORY}
 )
-execute_process(COMMAND ${BASH} -c ${CLEANUP_CMD}
-    WORKING_DIRECTORY ${WORKING_DIRECTORY}
-)
+if(DEFINED CLEANUP_CMD AND NOT CLEANUP_CMD STREQUAL "")
+    execute_process(COMMAND ${BASH} -c ${CLEANUP_CMD}
+        WORKING_DIRECTORY ${WORKING_DIRECTORY}
+    )
+endif()
 
 if(test_result_${FILE_PATH} EQUAL 0)
     message(STATUS "Test ${FILE_PATH} passed")
diff --git a/testing/binaries/CMakeLists.txt b/testing/binaries/CMakeLists.txt
index 3733e60728..7b2795a332 100644
--- a/testing/binaries/CMakeLists.txt
+++ b/testing/binaries/CMakeLists.txt
@@ -9,9 +9,16 @@ dirs_to_unix(EXEC_DIRS "${EXEC_DIRS}")
 
 include(BashTests)
 function(add_bash_binary_test file_path)
+    # Extra arguments are labels, except for the NO_FILESYSTEM_LOCK opt-out keyword
+    # which is forwarded to add_bash_test for tests that never write to disk.
     set(extra_labels "")
-    foreach(label ${ARGN})
-        list(APPEND extra_labels ${label})
+    set(no_filesystem_lock "")
+    foreach(arg ${ARGN})
+        if(arg STREQUAL "NO_FILESYSTEM_LOCK")
+            set(no_filesystem_lock NO_FILESYSTEM_LOCK)
+        else()
+            list(APPEND extra_labels ${arg})
+        endif()
     endforeach()
 
     # Set folder name
@@ -24,12 +31,13 @@ function(add_bash_binary_test file_path)
         WORKING_DIRECTORY ${BINARY_DATA_DIR}
         EXEC_DIRECTORIES "${EXEC_DIRS}"
         LABELS "binary;${folder_name};${extra_labels}"
+        ${no_filesystem_lock}
     )
 endfunction()
 
-add_bash_binary_test(5tt2gmwmi/default)
+add_bash_binary_test(5tt2gmwmi/default NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(5tt2vis/default)
+add_bash_binary_test(5tt2vis/default NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(5ttedit/onetissue)
 add_bash_binary_test(5ttedit/twotissues)
@@ -49,31 +57,31 @@ add_bash_binary_test(5ttvalidate/wrong_dimensionality)
 add_bash_binary_test(5ttvalidate/wrong_volumes)
 
 add_bash_binary_test(afdconnectivity/afd_map)
-add_bash_binary_test(afdconnectivity/default)
+add_bash_binary_test(afdconnectivity/default NO_FILESYSTEM_LOCK)
 add_bash_binary_test(afdconnectivity/wbft)
 
 add_bash_binary_test(amp2response/default)
 add_bash_binary_test(amp2response/lmax)
 add_bash_binary_test(amp2response/noconstraint)
 
-add_bash_binary_test(amp2sh/default)
-add_bash_binary_test(amp2sh/lmax)
-add_bash_binary_test(amp2sh/with_noise)
+add_bash_binary_test(amp2sh/default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(amp2sh/lmax NO_FILESYSTEM_LOCK)
+add_bash_binary_test(amp2sh/with_noise NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(connectome2tck/exemplars)
 add_bash_binary_test(connectome2tck/per_node)
 add_bash_binary_test(connectome2tck/single_edge)
 
-add_bash_binary_test(connectomeedit/lower_triangular_from_asymmetric)
+add_bash_binary_test(connectomeedit/lower_triangular_from_asymmetric NO_FILESYSTEM_LOCK)
 add_bash_binary_test(connectomeedit/lower_triangular_from_lower_triangular)
 add_bash_binary_test(connectomeedit/lower_triangular_from_symmetric)
 add_bash_binary_test(connectomeedit/lower_triangular_from_upper_triangular)
-add_bash_binary_test(connectomeedit/symmetric_from_asymmetric)
+add_bash_binary_test(connectomeedit/symmetric_from_asymmetric NO_FILESYSTEM_LOCK)
 add_bash_binary_test(connectomeedit/symmetric_from_lower_triangular)
 add_bash_binary_test(connectomeedit/symmetric_from_symmetric)
 add_bash_binary_test(connectomeedit/symmetric_from_upper_triangular)
 add_bash_binary_test(connectomeedit/transpose)
-add_bash_binary_test(connectomeedit/upper_triangular_from_asymmetric)
+add_bash_binary_test(connectomeedit/upper_triangular_from_asymmetric NO_FILESYSTEM_LOCK)
 add_bash_binary_test(connectomeedit/upper_triangular_from_lower_triangular)
 add_bash_binary_test(connectomeedit/upper_triangular_from_symmetric)
 add_bash_binary_test(connectomeedit/upper_triangular_from_upper_triangular)
@@ -122,65 +130,65 @@ add_bash_binary_test(dwi2adc/default)
 add_bash_binary_test(dwi2adc/ivim)
 
 add_bash_binary_test(dwi2fod/csd_default)
-add_bash_binary_test(dwi2fod/csd_lmax)
-add_bash_binary_test(dwi2fod/csd_masked)
+add_bash_binary_test(dwi2fod/csd_lmax NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwi2fod/csd_masked NO_FILESYSTEM_LOCK)
 add_bash_binary_test(dwi2fod/msmt_default)
 add_bash_binary_test(dwi2fod/msmt_masked)
 
 add_bash_binary_test(dwi2tensor/bzero)
-add_bash_binary_test(dwi2tensor/default)
+add_bash_binary_test(dwi2tensor/default NO_FILESYSTEM_LOCK)
 add_bash_binary_test(dwi2tensor/dkt_constrained)
 add_bash_binary_test(dwi2tensor/dkt_unconstrained)
-add_bash_binary_test(dwi2tensor/iters)
-add_bash_binary_test(dwi2tensor/masked)
-add_bash_binary_test(dwi2tensor/ols)
+add_bash_binary_test(dwi2tensor/iters NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwi2tensor/masked NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwi2tensor/ols NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(dwidenoise/default)
+add_bash_binary_test(dwidenoise/default NO_FILESYSTEM_LOCK)
 add_bash_binary_test(dwidenoise/exp1_estimator)
-add_bash_binary_test(dwidenoise/extent_anisotropic)
-add_bash_binary_test(dwidenoise/extent_isotropic)
-add_bash_binary_test(dwidenoise/masked)
+add_bash_binary_test(dwidenoise/extent_anisotropic NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwidenoise/extent_isotropic NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwidenoise/masked NO_FILESYSTEM_LOCK)
 add_bash_binary_test(dwidenoise/noise_default)
 add_bash_binary_test(dwidenoise/noise_extent)
 
-add_bash_binary_test(dwiextract/bzero)
-add_bash_binary_test(dwiextract/default)
+add_bash_binary_test(dwiextract/bzero NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwiextract/default NO_FILESYSTEM_LOCK)
 add_bash_binary_test(dwiextract/shells)
 add_bash_binary_test(dwiextract/singleshell)
 
-add_bash_binary_test(dwirecon/combinepairs_pequad)
-add_bash_binary_test(dwirecon/combinepairs_reordered)
-add_bash_binary_test(dwirecon/combinepairs_rpepair)
+add_bash_binary_test(dwirecon/combinepairs_pequad NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwirecon/combinepairs_reordered NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwirecon/combinepairs_rpepair NO_FILESYSTEM_LOCK)
 add_bash_binary_test(dwirecon/combinepairs_unbalanced)
 add_bash_binary_test(dwirecon/combinepredicted_exponent)
 add_bash_binary_test(dwirecon/combinepredicted_lmax)
-add_bash_binary_test(dwirecon/combinepredicted_pequad)
-add_bash_binary_test(dwirecon/combinepredicted_rpepair)
+add_bash_binary_test(dwirecon/combinepredicted_pequad NO_FILESYSTEM_LOCK)
+add_bash_binary_test(dwirecon/combinepredicted_rpepair NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(fixel2peaks/input_afd)
-add_bash_binary_test(fixel2peaks/input_directions)
-add_bash_binary_test(fixel2peaks/input_directory)
-add_bash_binary_test(fixel2peaks/input_index)
+add_bash_binary_test(fixel2peaks/input_afd NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2peaks/input_directions NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2peaks/input_directory NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2peaks/input_index NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(fixel2sh/default)
-add_bash_binary_test(fixel2sh/lmax)
+add_bash_binary_test(fixel2sh/default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2sh/lmax NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(fixel2tsf/default)
 
-add_bash_binary_test(fixel2voxel/absmax)
-add_bash_binary_test(fixel2voxel/complexity)
-add_bash_binary_test(fixel2voxel/count)
-add_bash_binary_test(fixel2voxel/dec_scaled)
-add_bash_binary_test(fixel2voxel/dec_unit)
-add_bash_binary_test(fixel2voxel/entropy)
-add_bash_binary_test(fixel2voxel/magmax)
-add_bash_binary_test(fixel2voxel/max)
-add_bash_binary_test(fixel2voxel/mean)
-add_bash_binary_test(fixel2voxel/min)
-add_bash_binary_test(fixel2voxel/none)
-add_bash_binary_test(fixel2voxel/product)
-add_bash_binary_test(fixel2voxel/sf)
-add_bash_binary_test(fixel2voxel/sum)
+add_bash_binary_test(fixel2voxel/absmax NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/complexity NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/count NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/dec_scaled NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/dec_unit NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/entropy NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/magmax NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/max NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/mean NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/min NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/none NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/product NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/sf NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fixel2voxel/sum NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(fixelcfestats/default)
 add_bash_binary_test(fixelcfestats/legacy)
@@ -197,10 +205,10 @@ add_bash_binary_test(fixelcrop/default)
 
 add_bash_binary_test(fixelfilter/cfe_default)
 add_bash_binary_test(fixelfilter/cfe_masked)
-add_bash_binary_test(fixelfilter/cfe_nan)
+add_bash_binary_test(fixelfilter/cfe_nan NO_FILESYSTEM_LOCK)
 add_bash_binary_test(fixelfilter/smooth_inputdir)
 add_bash_binary_test(fixelfilter/smooth_inputfile)
-add_bash_binary_test(fixelfilter/smooth_masked)
+add_bash_binary_test(fixelfilter/smooth_masked NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(fixelreorient/default)
 
@@ -215,34 +223,34 @@ add_bash_binary_test(fixelvalidate/malformed_index)
 add_bash_binary_test(fixelvalidate/missing_directions)
 add_bash_binary_test(fixelvalidate/wrong_nfixels)
 
-add_bash_binary_test(fod2dec/anat_combo)
-add_bash_binary_test(fod2dec/anat_default)
-add_bash_binary_test(fod2dec/anat_lum)
-add_bash_binary_test(fod2dec/anat_masked)
-add_bash_binary_test(fod2dec/anat_noweight)
-add_bash_binary_test(fod2dec/anat_threshold)
-add_bash_binary_test(fod2dec/combo)
-add_bash_binary_test(fod2dec/default)
-add_bash_binary_test(fod2dec/lum)
-add_bash_binary_test(fod2dec/masked)
-add_bash_binary_test(fod2dec/noweight)
-add_bash_binary_test(fod2dec/threshold)
+add_bash_binary_test(fod2dec/anat_combo NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/anat_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/anat_lum NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/anat_masked NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/anat_noweight NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/anat_threshold NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/combo NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/lum NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/masked NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/noweight NO_FILESYSTEM_LOCK)
+add_bash_binary_test(fod2dec/threshold NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(fod2fixel/default)
 add_bash_binary_test(fod2fixel/masked)
 add_bash_binary_test(fod2fixel/nothresholds)
 
-add_bash_binary_test(label2colour/freesurfer)
-add_bash_binary_test(label2colour/iit)
+add_bash_binary_test(label2colour/freesurfer NO_FILESYSTEM_LOCK)
+add_bash_binary_test(label2colour/iit NO_FILESYSTEM_LOCK)
 add_bash_binary_test(label2colour/random)
 
 add_bash_binary_test(label2mesh/blocky)
 add_bash_binary_test(label2mesh/default)
 
-add_bash_binary_test(labelconvert/aal)
-add_bash_binary_test(labelconvert/freesurfer)
-add_bash_binary_test(labelconvert/iit)
-add_bash_binary_test(labelconvert/lpba40)
+add_bash_binary_test(labelconvert/aal NO_FILESYSTEM_LOCK)
+add_bash_binary_test(labelconvert/freesurfer NO_FILESYSTEM_LOCK)
+add_bash_binary_test(labelconvert/iit NO_FILESYSTEM_LOCK)
+add_bash_binary_test(labelconvert/lpba40 NO_FILESYSTEM_LOCK)
 add_bash_binary_test(labelconvert/mismatch)
 
 add_bash_binary_test(labelstats/default)
@@ -260,18 +268,18 @@ add_bash_binary_test(labelvalidate/wrong_dimensionality)
 add_bash_binary_test(maskdump/output_file)
 add_bash_binary_test(maskdump/stdout)
 
-add_bash_binary_test(maskfilter/connect_26connectivity)
-add_bash_binary_test(maskfilter/connect_26connectivity_largest)
-add_bash_binary_test(maskfilter/connect_axes)
-add_bash_binary_test(maskfilter/connect_axes_26connectivity)
-add_bash_binary_test(maskfilter/connect_default)
-add_bash_binary_test(maskfilter/connect_largest)
-add_bash_binary_test(maskfilter/dilate)
-add_bash_binary_test(maskfilter/erode)
-add_bash_binary_test(maskfilter/median)
+add_bash_binary_test(maskfilter/connect_26connectivity NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/connect_26connectivity_largest NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/connect_axes NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/connect_axes_26connectivity NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/connect_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/connect_largest NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/dilate NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/erode NO_FILESYSTEM_LOCK)
+add_bash_binary_test(maskfilter/median NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(mesh2voxel/default)
-add_bash_binary_test(mesh2voxel/input_4D)
+add_bash_binary_test(mesh2voxel/default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mesh2voxel/input_4D NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(meshconvert/big_endian)
 add_bash_binary_test(meshconvert/little_endian)
@@ -295,54 +303,54 @@ add_bash_binary_test(meshvalidate/duplicate_polygon)
 add_bash_binary_test(meshvalidate/duplicate_vertex)
 add_bash_binary_test(meshvalidate/inconsistent_normals)
 
-add_bash_binary_test(mraverageheader/mean_nearest)
-add_bash_binary_test(mraverageheader/mean_projection)
-add_bash_binary_test(mraverageheader/min_nearest)
-add_bash_binary_test(mraverageheader/min_projection)
-add_bash_binary_test(mraverageheader/padding)
+add_bash_binary_test(mraverageheader/mean_nearest NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mraverageheader/mean_projection NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mraverageheader/min_nearest NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mraverageheader/min_projection NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mraverageheader/padding NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mraverageheader/4D)
 
-add_bash_binary_test(mrcalc/calc_mode)
-add_bash_binary_test(mrcalc/dwscheme_preservation_imprecision)
-add_bash_binary_test(mrcalc/expression_1)
-add_bash_binary_test(mrcalc/expression_2)
-add_bash_binary_test(mrcalc/expression_3)
-add_bash_binary_test(mrcalc/expression_4)
-add_bash_binary_test(mrcalc/expression_5)
+add_bash_binary_test(mrcalc/calc_mode NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcalc/expression_1 NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcalc/expression_2 NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcalc/expression_3 NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcalc/expression_4 NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcalc/expression_5 NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcalc/dwscheme_preservation_imprecision NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mrcat/axis)
 add_bash_binary_test(mrcat/dwscheme_merge)
-add_bash_binary_test(mrcat/single_input)
-add_bash_binary_test(mrcat/singlevoxel)
+add_bash_binary_test(mrcat/single_input NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcat/singlevoxel NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mrcentroid/default)
 add_bash_binary_test(mrcentroid/voxelspace)
 add_bash_binary_test(mrcentroid/with_mask)
 
-add_bash_binary_test(mrcheckerboardmask/default)
+add_bash_binary_test(mrcheckerboardmask/default NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrcheckerboardmask/invert)
 add_bash_binary_test(mrcheckerboardmask/nan)
-add_bash_binary_test(mrcheckerboardmask/tiles)
+add_bash_binary_test(mrcheckerboardmask/tiles NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mrclusterstats/clustersize)
 add_bash_binary_test(mrclusterstats/default)
 add_bash_binary_test(mrclusterstats/masked)
 add_bash_binary_test(mrclusterstats/posthoc)
 
-add_bash_binary_test(mrcolour/bothlimits)
+add_bash_binary_test(mrcolour/bothlimits NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrcolour/fixed_colour)
-add_bash_binary_test(mrcolour/map_cool)
-add_bash_binary_test(mrcolour/map_gray)
-add_bash_binary_test(mrcolour/map_hot)
-add_bash_binary_test(mrcolour/map_inferno)
-add_bash_binary_test(mrcolour/map_jet)
-add_bash_binary_test(mrcolour/map_pet)
+add_bash_binary_test(mrcolour/map_cool NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcolour/map_gray NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcolour/map_hot NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcolour/map_inferno NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcolour/map_jet NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrcolour/map_pet NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrcolour/map_rgb)
-add_bash_binary_test(mrcolour/map_viridis)
+add_bash_binary_test(mrcolour/map_viridis NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrcolour/scaling)
-add_bash_binary_test(mrcolour/upperlimit)
+add_bash_binary_test(mrcolour/upperlimit NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(mrconvert/big_endian)
+add_bash_binary_test(mrconvert/big_endian NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrconvert/coord_end)
 add_bash_binary_test(mrconvert/format_mgh)
 add_bash_binary_test(mrconvert/format_mgz)
@@ -351,64 +359,64 @@ add_bash_binary_test(mrconvert/format_mih)
 add_bash_binary_test(mrconvert/format_nii)
 add_bash_binary_test(mrconvert/format_nii_gz)
 add_bash_binary_test(mrconvert/format_png)
-add_bash_binary_test(mrconvert/insert_axis)
+add_bash_binary_test(mrconvert/insert_axis NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrconvert/multifile)
 add_bash_binary_test(mrconvert/multifile_singlevoxel)
-add_bash_binary_test(mrconvert/passthrough)
-add_bash_binary_test(mrconvert/real2complex)
-add_bash_binary_test(mrconvert/strides)
+add_bash_binary_test(mrconvert/passthrough NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrconvert/real2complex NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrconvert/strides NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mrdegibbs/3D)
-add_bash_binary_test(mrdegibbs/default)
-add_bash_binary_test(mrdegibbs/axes_explicit)
+add_bash_binary_test(mrdegibbs/axes_explicit NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrdegibbs/default NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mrdump/masked)
 add_bash_binary_test(mrdump/output_file)
 add_bash_binary_test(mrdump/stdout)
 
 add_bash_binary_test(mredit/plane)
-add_bash_binary_test(mredit/sphere)
+add_bash_binary_test(mredit/sphere NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mredit/voxel)
 
-add_bash_binary_test(mrfilter/demodulate_3Din_linear_2Ddemod)
-add_bash_binary_test(mrfilter/demodulate_3Din_linear_3Ddemod)
-add_bash_binary_test(mrfilter/demodulate_3Din_nonlinear_2Ddemod)
-add_bash_binary_test(mrfilter/demodulate_3Din_nonlinear_3Ddemod)
-add_bash_binary_test(mrfilter/demodulate_4Din_linear_2Ddemod)
-add_bash_binary_test(mrfilter/demodulate_4Din_linear_3Ddemod)
-add_bash_binary_test(mrfilter/demodulate_4Din_nonlinear_2Ddemod)
-add_bash_binary_test(mrfilter/demodulate_4Din_nonlinear_3Ddemod)
+add_bash_binary_test(mrfilter/demodulate_3Din_linear_2Ddemod NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/demodulate_3Din_linear_3Ddemod NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/demodulate_3Din_nonlinear_2Ddemod NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/demodulate_3Din_nonlinear_3Ddemod NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/demodulate_4Din_linear_2Ddemod NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/demodulate_4Din_linear_3Ddemod NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/demodulate_4Din_nonlinear_2Ddemod NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/demodulate_4Din_nonlinear_3Ddemod NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrfilter/gradient_default)
 add_bash_binary_test(mrfilter/gradient_magnitude)
 add_bash_binary_test(mrfilter/gradient_scanner)
 add_bash_binary_test(mrfilter/gradient_scanner_magnitude)
-add_bash_binary_test(mrfilter/median_default)
-add_bash_binary_test(mrfilter/median_extent_anisotropic)
-add_bash_binary_test(mrfilter/median_extent_isotropic)
-add_bash_binary_test(mrfilter/normalise)
-add_bash_binary_test(mrfilter/smooth_default)
-add_bash_binary_test(mrfilter/smooth_extent)
-add_bash_binary_test(mrfilter/smooth_fwhm)
-add_bash_binary_test(mrfilter/smooth_stdev_3vector)
-add_bash_binary_test(mrfilter/smooth_stdev_anisotropic)
-add_bash_binary_test(mrfilter/smooth_stdev_scalar)
-
-add_bash_binary_test(mrgrid/crop_axis_range)
-add_bash_binary_test(mrgrid/crop_axis_widths)
-add_bash_binary_test(mrgrid/crop_mask_default)
-add_bash_binary_test(mrgrid/crop_mask_nopadding)
-add_bash_binary_test(mrgrid/pad_singleaxis)
-add_bash_binary_test(mrgrid/pad_twoaxes)
-add_bash_binary_test(mrgrid/pad_uniform)
-add_bash_binary_test(mrgrid/pad_uniform_plus_singleaxis)
-add_bash_binary_test(mrgrid/regrid_anisotropic_scale)
-add_bash_binary_test(mrgrid/regrid_anisotropic_size)
-add_bash_binary_test(mrgrid/regrid_anisotropic_vox)
-add_bash_binary_test(mrgrid/regrid_downsample)
-add_bash_binary_test(mrgrid/regrid_upsample_default)
-add_bash_binary_test(mrgrid/regrid_upsample_linear)
-add_bash_binary_test(mrgrid/regrid_upsample_nearest)
-add_bash_binary_test(mrgrid/regrid_upsample_sinc)
+add_bash_binary_test(mrfilter/median_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/median_extent_anisotropic NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/median_extent_isotropic NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/normalise NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/smooth_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/smooth_extent NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/smooth_fwhm NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/smooth_stdev_3vector NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/smooth_stdev_anisotropic NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrfilter/smooth_stdev_scalar NO_FILESYSTEM_LOCK)
+
+add_bash_binary_test(mrgrid/crop_axis_range NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/crop_axis_widths NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/crop_mask_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/crop_mask_nopadding NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/pad_singleaxis NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/pad_twoaxes NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/pad_uniform NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/pad_uniform_plus_singleaxis NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_anisotropic_scale NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_anisotropic_size NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_anisotropic_vox NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_downsample NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_upsample_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_upsample_linear NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_upsample_nearest NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrgrid/regrid_upsample_sinc NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mrhistmatch/linear)
 add_bash_binary_test(mrhistmatch/linear_with_masks)
@@ -420,7 +428,7 @@ add_bash_binary_test(mrhistogram/bins)
 add_bash_binary_test(mrhistogram/default)
 add_bash_binary_test(mrhistogram/masked)
 
-add_bash_binary_test(mrinfo/all)
+add_bash_binary_test(mrinfo/all NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrinfo/bvec_bval_nan)
 add_bash_binary_test(mrinfo/json_keyval)
 add_bash_binary_test(mrinfo/print_fields)
@@ -430,11 +438,11 @@ add_bash_binary_test(mrmath/max)
 add_bash_binary_test(mrmath/median)
 add_bash_binary_test(mrmath/min)
 add_bash_binary_test(mrmath/multiimage_median)
-add_bash_binary_test(mrmath/singleimage_mean)
-add_bash_binary_test(mrmath/singleimage_norm)
-add_bash_binary_test(mrmath/singleimage_rms)
-add_bash_binary_test(mrmath/std)
-add_bash_binary_test(mrmath/var)
+add_bash_binary_test(mrmath/singleimage_mean NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrmath/singleimage_norm NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrmath/singleimage_rms NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrmath/std NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrmath/var NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mrmetric/diff_average_space)
 add_bash_binary_test(mrmetric/diff_image1_space)
@@ -442,70 +450,70 @@ add_bash_binary_test(mrmetric/diff_voxel)
 add_bash_binary_test(mrmetric/overlap)
 
 add_bash_binary_test(mrregister/affine_midway)
-add_bash_binary_test(mrregister/multicontrast_affine)
-add_bash_binary_test(mrregister/multicontrast_affine_weights)
+add_bash_binary_test(mrregister/multicontrast_affine NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrregister/multicontrast_affine_weights NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrregister/multicontrast_rigidaffine_fod)
 add_bash_binary_test(mrregister/multicontrast_rigidnonlinear_fod)
-add_bash_binary_test(mrregister/rigid)
-add_bash_binary_test(mrregister/singlecontrast_affine)
+add_bash_binary_test(mrregister/rigid NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrregister/singlecontrast_affine NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrregister/singlecontrast_rigidnonlinear_fod)
 
 add_bash_binary_test(mrstats/complex)
 add_bash_binary_test(mrstats/default)
 add_bash_binary_test(mrstats/masked)
 
-add_bash_binary_test(mrthreshold/3d_4dmask)
-add_bash_binary_test(mrthreshold/3d_abs)
-add_bash_binary_test(mrthreshold/3d_bottomcount)
-add_bash_binary_test(mrthreshold/3d_bottompercent)
-add_bash_binary_test(mrthreshold/3d_default_noimageout)
-add_bash_binary_test(mrthreshold/3d_default_withimageout)
+add_bash_binary_test(mrthreshold/3d_4dmask NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_abs NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_bottomcount NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_bottompercent NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_default_noimageout NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_default_withimageout NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrthreshold/3d_ignorezero)
-add_bash_binary_test(mrthreshold/3d_lessthan)
-add_bash_binary_test(mrthreshold/3d_masked)
-add_bash_binary_test(mrthreshold/3d_median)
-add_bash_binary_test(mrthreshold/3d_median_masked)
+add_bash_binary_test(mrthreshold/3d_lessthan NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_masked NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_median NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_median_masked NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrthreshold/3d_outmasked)
-add_bash_binary_test(mrthreshold/3d_topcount)
-add_bash_binary_test(mrthreshold/3d_toppercent)
-add_bash_binary_test(mrthreshold/4d_default_noimageout)
-add_bash_binary_test(mrthreshold/4d_default_withimageout)
-add_bash_binary_test(mrthreshold/4d_masked)
-add_bash_binary_test(mrthreshold/4d_median)
-add_bash_binary_test(mrthreshold/4d_median_masked)
+add_bash_binary_test(mrthreshold/3d_topcount NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/3d_toppercent NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/4d_default_noimageout NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/4d_default_withimageout NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/4d_masked NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/4d_median NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/4d_median_masked NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrthreshold/4d_verify_pervolume)
-add_bash_binary_test(mrthreshold/allvolumes_default)
-add_bash_binary_test(mrthreshold/allvolumes_masked)
-add_bash_binary_test(mrthreshold/allvolumes_median)
-add_bash_binary_test(mrthreshold/allvolumes_median_masked)
-
-add_bash_binary_test(mrtransform/fliplr)
-add_bash_binary_test(mrtransform/fod_linear_reorient_noresample)
-add_bash_binary_test(mrtransform/fod_linear_reorient_withresample)
-add_bash_binary_test(mrtransform/fod_nonlinear)
-add_bash_binary_test(mrtransform/identity)
-add_bash_binary_test(mrtransform/interp_sinc)
-add_bash_binary_test(mrtransform/linear)
+add_bash_binary_test(mrthreshold/allvolumes_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/allvolumes_masked NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/allvolumes_median NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrthreshold/allvolumes_median_masked NO_FILESYSTEM_LOCK)
+
+add_bash_binary_test(mrtransform/fliplr NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrtransform/fod_linear_reorient_noresample NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrtransform/fod_linear_reorient_withresample NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrtransform/fod_nonlinear NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrtransform/identity NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrtransform/interp_sinc NO_FILESYSTEM_LOCK)
+add_bash_binary_test(mrtransform/linear NO_FILESYSTEM_LOCK)
 add_bash_binary_test(mrtransform/linear_inverse)
 add_bash_binary_test(mrtransform/linear_template)
 add_bash_binary_test(mrtransform/noop)
-add_bash_binary_test(mrtransform/replace)
+add_bash_binary_test(mrtransform/replace NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(mtnormalise/default)
 
-add_bash_binary_test(peaks2amp/default)
+add_bash_binary_test(peaks2amp/default NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(peaks2fixel/default)
 
-add_bash_binary_test(peaksconvert/default_to_fsl3vector)
-add_bash_binary_test(peaksconvert/default_to_ijk3vector)
-add_bash_binary_test(peaksconvert/default_to_spherical)
+add_bash_binary_test(peaksconvert/default_to_fsl3vector NO_FILESYSTEM_LOCK)
+add_bash_binary_test(peaksconvert/default_to_ijk3vector NO_FILESYSTEM_LOCK)
+add_bash_binary_test(peaksconvert/default_to_spherical NO_FILESYSTEM_LOCK)
 add_bash_binary_test(peaksconvert/default_to_unit3vector)
-add_bash_binary_test(peaksconvert/default_to_unitspherical)
-add_bash_binary_test(peaksconvert/fsl3vector_to_default)
-add_bash_binary_test(peaksconvert/ijk3vector_to_default)
-add_bash_binary_test(peaksconvert/passthrough)
-add_bash_binary_test(peaksconvert/spherical_to_default)
+add_bash_binary_test(peaksconvert/default_to_unitspherical NO_FILESYSTEM_LOCK)
+add_bash_binary_test(peaksconvert/fsl3vector_to_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(peaksconvert/ijk3vector_to_default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(peaksconvert/passthrough NO_FILESYSTEM_LOCK)
+add_bash_binary_test(peaksconvert/spherical_to_default NO_FILESYSTEM_LOCK)
 add_bash_binary_test(peaksconvert/unitspherical_to_default)
 
 add_bash_binary_test(peaksvalidate/default)
@@ -517,27 +525,27 @@ add_bash_binary_test(peaksvalidate/numvolumes)
 add_bash_binary_test(peaksvalidate/partial_nan)
 add_bash_binary_test(peaksvalidate/unity_norm)
 
-add_bash_binary_test(sh2amp/default)
-add_bash_binary_test(sh2amp/grad)
-add_bash_binary_test(sh2amp/msmt)
-add_bash_binary_test(sh2amp/nonnegative)
+add_bash_binary_test(sh2amp/default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2amp/grad NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2amp/msmt NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2amp/nonnegative NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(sh2metric/entropy)
+add_bash_binary_test(sh2metric/entropy NO_FILESYSTEM_LOCK)
 add_bash_binary_test(sh2metric/entropy_directions)
-add_bash_binary_test(sh2metric/entropy_invnorm)
-add_bash_binary_test(sh2metric/entropy_multiinput)
-add_bash_binary_test(sh2metric/entropy_normalised)
-add_bash_binary_test(sh2metric/power)
-
-add_bash_binary_test(sh2peaks/default)
-add_bash_binary_test(sh2peaks/fast)
-add_bash_binary_test(sh2peaks/npeaks)
+add_bash_binary_test(sh2metric/entropy_invnorm NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2metric/entropy_multiinput NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2metric/entropy_normalised NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2metric/power NO_FILESYSTEM_LOCK)
+
+add_bash_binary_test(sh2peaks/default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2peaks/fast NO_FILESYSTEM_LOCK)
+add_bash_binary_test(sh2peaks/npeaks NO_FILESYSTEM_LOCK)
 add_bash_binary_test(sh2peaks/with_mask)
 
 add_bash_binary_test(sh2response/default)
 
-add_bash_binary_test(shconv/default)
-add_bash_binary_test(shconv/msmt)
+add_bash_binary_test(shconv/default NO_FILESYSTEM_LOCK)
+add_bash_binary_test(shconv/msmt NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(tck2connectome/assignment_forward_search)
 add_bash_binary_test(tck2connectome/default)
@@ -589,12 +597,12 @@ add_bash_binary_test(tckglobal/default)
 add_bash_binary_test(tckglobal/masked)
 add_bash_binary_test(tckglobal/multitissue)
 
-add_bash_binary_test(tckmap/dec)
-add_bash_binary_test(tckmap/default_template)
-add_bash_binary_test(tckmap/default_vox)
-add_bash_binary_test(tckmap/length)
-add_bash_binary_test(tckmap/scalar_map)
-add_bash_binary_test(tckmap/tod)
+add_bash_binary_test(tckmap/dec NO_FILESYSTEM_LOCK)
+add_bash_binary_test(tckmap/default_template NO_FILESYSTEM_LOCK)
+add_bash_binary_test(tckmap/default_vox NO_FILESYSTEM_LOCK)
+add_bash_binary_test(tckmap/length NO_FILESYSTEM_LOCK)
+add_bash_binary_test(tckmap/scalar_map NO_FILESYSTEM_LOCK)
+add_bash_binary_test(tckmap/tod NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(tckresample/downsample)
 add_bash_binary_test(tckresample/endpoints)
@@ -647,11 +655,11 @@ add_bash_binary_test(tckvalidate/novertices)
 add_bash_binary_test(tckvalidate/onevertex)
 add_bash_binary_test(tckvalidate/partialfinite)
 
-add_bash_binary_test(tensor2metric/adc)
+add_bash_binary_test(tensor2metric/adc NO_FILESYSTEM_LOCK)
 add_bash_binary_test(tensor2metric/dkt)
-add_bash_binary_test(tensor2metric/eigenvalues)
-add_bash_binary_test(tensor2metric/eigenvectors)
-add_bash_binary_test(tensor2metric/fa)
+add_bash_binary_test(tensor2metric/eigenvalues NO_FILESYSTEM_LOCK)
+add_bash_binary_test(tensor2metric/eigenvectors NO_FILESYSTEM_LOCK)
+add_bash_binary_test(tensor2metric/fa NO_FILESYSTEM_LOCK)
 add_bash_binary_test(tensor2metric/mo_na)
 
 add_bash_binary_test(transformcalc/average)
@@ -660,10 +668,10 @@ add_bash_binary_test(transformcalc/header)
 add_bash_binary_test(transformcalc/interpolate)
 add_bash_binary_test(transformcalc/invert)
 
-add_bash_binary_test(transformcompose/affine_nonlinear)
-add_bash_binary_test(transformcompose/affine_to_image)
+add_bash_binary_test(transformcompose/affine_nonlinear NO_FILESYSTEM_LOCK)
+add_bash_binary_test(transformcompose/affine_to_image NO_FILESYSTEM_LOCK)
 add_bash_binary_test(transformcompose/two_affines)
-add_bash_binary_test(transformcompose/two_nonlinear)
+add_bash_binary_test(transformcompose/two_nonlinear NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(transformconvert/flirt_import)
 add_bash_binary_test(transformconvert/itk_ants)
@@ -700,23 +708,23 @@ add_bash_binary_test(voxel2mesh/blocky)
 add_bash_binary_test(voxel2mesh/default)
 
 add_bash_binary_test(warp2metric/fc)
-add_bash_binary_test(warp2metric/jdet)
-add_bash_binary_test(warp2metric/jmat)
+add_bash_binary_test(warp2metric/jdet NO_FILESYSTEM_LOCK)
+add_bash_binary_test(warp2metric/jmat NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(warpconvert/deformation2displacement)
-add_bash_binary_test(warpconvert/displacement2deformation)
-add_bash_binary_test(warpconvert/warpfull2deformation)
-add_bash_binary_test(warpconvert/warpfull2displacement)
+add_bash_binary_test(warpconvert/deformation2displacement NO_FILESYSTEM_LOCK)
+add_bash_binary_test(warpconvert/displacement2deformation NO_FILESYSTEM_LOCK)
+add_bash_binary_test(warpconvert/warpfull2deformation NO_FILESYSTEM_LOCK)
+add_bash_binary_test(warpconvert/warpfull2displacement NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(warpcorrect/default)
+add_bash_binary_test(warpcorrect/default NO_FILESYSTEM_LOCK)
 add_bash_binary_test(warpcorrect/with_marker)
 
-add_bash_binary_test(warpinit/default)
+add_bash_binary_test(warpinit/default NO_FILESYSTEM_LOCK)
 
-add_bash_binary_test(warpinvert/deformation)
-add_bash_binary_test(warpinvert/displacement)
-add_bash_binary_test(warpinvert/noop)
-add_bash_binary_test(warpinvert/roundtrip)
+add_bash_binary_test(warpinvert/deformation NO_FILESYSTEM_LOCK)
+add_bash_binary_test(warpinvert/displacement NO_FILESYSTEM_LOCK)
+add_bash_binary_test(warpinvert/noop NO_FILESYSTEM_LOCK)
+add_bash_binary_test(warpinvert/roundtrip NO_FILESYSTEM_LOCK)
 
 add_bash_binary_test(warpvalidate/deformation)
 add_bash_binary_test(warpvalidate/deformation_volumecount)
@@ -725,6 +733,6 @@ add_bash_binary_test(warpvalidate/fillconflict)
 add_bash_binary_test(warpvalidate/fillnan)
 add_bash_binary_test(warpvalidate/full)
 add_bash_binary_test(warpvalidate/full_nolinearxfm)
+add_bash_binary_test(warpvalidate/full_volumecount)
 add_bash_binary_test(warpvalidate/nonrealfloat)
 add_bash_binary_test(warpvalidate/partialfinite)
-add_bash_binary_test(warpvalidate/full_volumecount)
diff --git a/testing/integration_tests/CMakeLists.txt b/testing/integration_tests/CMakeLists.txt
index 9fda731e89..8a2294e1bf 100644
--- a/testing/integration_tests/CMakeLists.txt
+++ b/testing/integration_tests/CMakeLists.txt
@@ -41,6 +41,13 @@ dirs_to_unix(EXEC_DIRS "${EXEC_DIRS}")
 include(BashTests)
 function (add_bash_integration_test FILE_SRC)
     get_filename_component(NAME ${FILE_SRC} NAME_WE)
+    # Forward the NO_FILESYSTEM_LOCK opt-out keyword for tests that never write to disk.
+    set(no_filesystem_lock "")
+    foreach(arg ${ARGN})
+        if(arg STREQUAL "NO_FILESYSTEM_LOCK")
+            set(no_filesystem_lock NO_FILESYSTEM_LOCK)
+        endif()
+    endforeach()
     add_bash_test(
         FILE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/${FILE_SRC}"
         PREFIX "integrationtest"
@@ -48,6 +55,7 @@ function (add_bash_integration_test FILE_SRC)
         EXEC_DIRECTORIES "${EXEC_DIRS}"
         ENVIRONMENT "PYTHONPATH=${PYTHON_ENV_PATH}"
         LABELS "integration;${NAME}"
+        ${no_filesystem_lock}
     )
 endfunction()
 
diff --git a/testing/scripts/CMakeLists.txt b/testing/scripts/CMakeLists.txt
index 941e57f29d..df6ff25cd8 100644
--- a/testing/scripts/CMakeLists.txt
+++ b/testing/scripts/CMakeLists.txt
@@ -9,9 +9,16 @@ dirs_to_unix(EXEC_DIRS "${EXEC_DIRS}")
 
 include(BashTests)
 function(add_bash_script_test file_path)
+    # Extra arguments are labels, except for the NO_FILESYSTEM_LOCK opt-out keyword
+    # which is forwarded to add_bash_test for tests that never write to disk.
     set(extra_labels "")
-    foreach(label ${ARGN})
-        list(APPEND extra_labels ${label})
+    set(no_filesystem_lock "")
+    foreach(arg ${ARGN})
+        if(arg STREQUAL "NO_FILESYSTEM_LOCK")
+            set(no_filesystem_lock NO_FILESYSTEM_LOCK)
+        else()
+            list(APPEND extra_labels ${arg})
+        endif()
     endforeach()
 
     # Set folder name
@@ -24,33 +31,33 @@ function(add_bash_script_test file_path)
         WORKING_DIRECTORY ${SCRIPT_DATA_DIR}
         EXEC_DIRECTORIES "${EXEC_DIRS}"
         LABELS "script;${folder_name};${extra_labels}"
+        ${no_filesystem_lock}
     )
 endfunction()
 
-add_bash_script_test(5ttgen/deepatropos_fromseg_default "pythonci")
-add_bash_script_test(5ttgen/deepatropos_fromseg_whitestem)
-add_bash_script_test(5ttgen/deepatropos_fromprob_default "pythonci")
-add_bash_script_test(5ttgen/deepatropos_fromprob_whitestem)
-add_bash_script_test(5ttgen/freesurfer_default "pythonci")
-add_bash_script_test(5ttgen/freesurfer_nocrop)
-add_bash_script_test(5ttgen/freesurfer_piping)
-add_bash_script_test(5ttgen/freesurfer_sgmamyghipp)
+add_bash_script_test(5ttgen/deepatropos_fromseg_default "pythonci" NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/deepatropos_fromseg_whitestem NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/deepatropos_fromprob_default "pythonci" NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/deepatropos_fromprob_whitestem NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/freesurfer_default "pythonci" NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/freesurfer_nocrop NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/freesurfer_piping NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/freesurfer_sgmamyghipp NO_FILESYSTEM_LOCK)
 add_bash_script_test(5ttgen/freesurfer_whitespace)
 add_bash_script_test(5ttgen/fsl_default)
-add_bash_script_test(5ttgen/fsl_mask)
-add_bash_script_test(5ttgen/fsl_nocrop)
+add_bash_script_test(5ttgen/fsl_mask NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/fsl_nocrop NO_FILESYSTEM_LOCK)
 add_bash_script_test(5ttgen/fsl_piping)
 add_bash_script_test(5ttgen/fsl_premasked)
 add_bash_script_test(5ttgen/fsl_sgmamyghipp)
 add_bash_script_test(5ttgen/fsl_whitespace)
-add_bash_script_test(5ttgen/hsvs_aseg)
-add_bash_script_test(5ttgen/hsvs_default)
-add_bash_script_test(5ttgen/hsvs_first)
-add_bash_script_test(5ttgen/hsvs_modules)
-add_bash_script_test(5ttgen/hsvs_piping)
-add_bash_script_test(5ttgen/hsvs_template)
+add_bash_script_test(5ttgen/hsvs_aseg NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/hsvs_default NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/hsvs_first NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/hsvs_modules NO_FILESYSTEM_LOCK)
+add_bash_script_test(5ttgen/hsvs_template NO_FILESYSTEM_LOCK)
 add_bash_script_test(5ttgen/hsvs_whitespace)
-add_bash_script_test(5ttgen/hsvs_whitestem)
+add_bash_script_test(5ttgen/hsvs_whitestem NO_FILESYSTEM_LOCK)
 
 add_bash_script_test(dwi2mask/3dautomask_default)
 add_bash_script_test(dwi2mask/3dautomask_options)
@@ -86,11 +93,11 @@ add_bash_script_test(dwi2mask/fslbet_whitespace)
 add_bash_script_test(dwi2mask/hdbet_default)
 add_bash_script_test(dwi2mask/hdbet_piping)
 add_bash_script_test(dwi2mask/hdbet_whitespace)
-add_bash_script_test(dwi2mask/legacy_default "pythonci")
-add_bash_script_test(dwi2mask/legacy_piping)
+add_bash_script_test(dwi2mask/legacy_default "pythonci" NO_FILESYSTEM_LOCK)
+add_bash_script_test(dwi2mask/legacy_piping NO_FILESYSTEM_LOCK)
 add_bash_script_test(dwi2mask/legacy_whitespace)
-add_bash_script_test(dwi2mask/mean_default "pythonci")
-add_bash_script_test(dwi2mask/mean_piping)
+add_bash_script_test(dwi2mask/mean_default "pythonci" NO_FILESYSTEM_LOCK)
+add_bash_script_test(dwi2mask/mean_piping NO_FILESYSTEM_LOCK)
 add_bash_script_test(dwi2mask/mean_whitespace)
 add_bash_script_test(dwi2mask/mtnorm_default "pythonci")
 add_bash_script_test(dwi2mask/mtnorm_initmask)
@@ -101,9 +108,9 @@ add_bash_script_test(dwi2mask/synthstrip_default)
 add_bash_script_test(dwi2mask/synthstrip_options)
 add_bash_script_test(dwi2mask/synthstrip_piping)
 add_bash_script_test(dwi2mask/synthstrip_whitespace)
-add_bash_script_test(dwi2mask/trace_default "pythonci")
-add_bash_script_test(dwi2mask/trace_iterative)
-add_bash_script_test(dwi2mask/trace_piping)
+add_bash_script_test(dwi2mask/trace_default "pythonci" NO_FILESYSTEM_LOCK)
+add_bash_script_test(dwi2mask/trace_iterative NO_FILESYSTEM_LOCK)
+add_bash_script_test(dwi2mask/trace_piping NO_FILESYSTEM_LOCK)
 add_bash_script_test(dwi2mask/trace_whitespace)
 
 add_bash_script_test(dwi2response/dhollander_default)
@@ -209,14 +216,14 @@ add_bash_script_test(dwifslpreproc/topup_files)
 add_bash_script_test(dwifslpreproc/whitespace)
 
 add_bash_script_test(dwigradcheck/default)
-add_bash_script_test(dwigradcheck/piping)
+add_bash_script_test(dwigradcheck/piping NO_FILESYSTEM_LOCK)
 add_bash_script_test(dwigradcheck/whitespace)
 
 add_bash_script_test(dwinormalise/group_default "pythonci")
 add_bash_script_test(dwinormalise/group_piping)
 add_bash_script_test(dwinormalise/group_whitespace)
 add_bash_script_test(dwinormalise/manual_default "pythonci")
-add_bash_script_test(dwinormalise/manual_percentile)
+add_bash_script_test(dwinormalise/manual_percentile NO_FILESYSTEM_LOCK)
 add_bash_script_test(dwinormalise/manual_piping)
 add_bash_script_test(dwinormalise/manual_whitespace)
 add_bash_script_test(dwinormalise/mtnorm_default "pythonci")
@@ -236,16 +243,16 @@ add_bash_script_test(for_each/echo "pythonci")
 add_bash_script_test(for_each/exclude "pythonci")
 add_bash_script_test(for_each/parallel "pythonci")
 
-add_bash_script_test(labelsgmfirst/default)
-add_bash_script_test(labelsgmfirst/freesurfer)
+add_bash_script_test(labelsgmfirst/default NO_FILESYSTEM_LOCK)
+add_bash_script_test(labelsgmfirst/freesurfer NO_FILESYSTEM_LOCK)
 add_bash_script_test(labelsgmfirst/piping)
 add_bash_script_test(labelsgmfirst/premasked)
-add_bash_script_test(labelsgmfirst/sgm_amyg_hipp)
+add_bash_script_test(labelsgmfirst/sgm_amyg_hipp NO_FILESYSTEM_LOCK)
 add_bash_script_test(labelsgmfirst/whitespace)
 
-add_bash_script_test(mask2glass/default "pythonci")
+add_bash_script_test(mask2glass/default "pythonci" NO_FILESYSTEM_LOCK)
 add_bash_script_test(mask2glass/no4dseries "pythonci")
-add_bash_script_test(mask2glass/piping)
+add_bash_script_test(mask2glass/piping NO_FILESYSTEM_LOCK)
 add_bash_script_test(mask2glass/whitespace)
 
 add_bash_script_test(mrtrix_cleanup/default "pythonci")
@@ -254,13 +261,13 @@ add_bash_script_test(mrtrix_cleanup/whitespace)
 
 add_bash_script_test(peakscheck/3vector_permutation)
 add_bash_script_test(peakscheck/all)
-add_bash_script_test(peakscheck/default)
-add_bash_script_test(peakscheck/mask)
+add_bash_script_test(peakscheck/default NO_FILESYSTEM_LOCK)
+add_bash_script_test(peakscheck/mask NO_FILESYSTEM_LOCK)
 add_bash_script_test(peakscheck/noshuffle "pythonci")
 add_bash_script_test(peakscheck/notransform "pythonci")
 add_bash_script_test(peakscheck/out_table)
 add_bash_script_test(peakscheck/reference)
-add_bash_script_test(peakscheck/spherical)
+add_bash_script_test(peakscheck/spherical NO_FILESYSTEM_LOCK)
 add_bash_script_test(peakscheck/spherical_permutation)
 
 add_bash_script_test(population_template/fa_affine)
diff --git a/testing/scripts/tests/5ttgen/deepatropos_fromprob_default b/testing/scripts/tests/5ttgen/deepatropos_fromprob_default
index 5778dd6eb3..ac2e95dea1 100644
--- a/testing/scripts/tests/5ttgen/deepatropos_fromprob_default
+++ b/testing/scripts/tests/5ttgen/deepatropos_fromprob_default
@@ -2,5 +2,5 @@
 # Verify default operation of "5ttgen deep_atropos"
 #   where the input is the concatenation of tissue probability images
 # Outcome is compared to that generated using a prior software version
-5ttgen deep_atropos 5ttgen/deep_atropos/probability_images.nii.gz tmp.mif -force
-testing_diff_image tmp.mif 5ttgen/deep_atropos/fromprob_default.mif.gz
+5ttgen deep_atropos 5ttgen/deep_atropos/probability_images.nii.gz - | \
+testing_diff_image - 5ttgen/deep_atropos/fromprob_default.mif.gz
diff --git a/testing/scripts/tests/5ttgen/deepatropos_fromprob_whitestem b/testing/scripts/tests/5ttgen/deepatropos_fromprob_whitestem
index 2ec776a17b..dc80ff6737 100644
--- a/testing/scripts/tests/5ttgen/deepatropos_fromprob_whitestem
+++ b/testing/scripts/tests/5ttgen/deepatropos_fromprob_whitestem
@@ -3,5 +3,5 @@
 #   where the input is the concatenation of tissue probability images
 #   and the brain stem is allocated to WM rather than 5th volume
 # Outcome is compared to that generated using a prior software version
-5ttgen deep_atropos 5ttgen/deep_atropos/probability_images.nii.gz tmp.mif -white_stem -force
-testing_diff_image tmp.mif 5ttgen/deep_atropos/fromprob_whitestem.mif.gz
+5ttgen deep_atropos 5ttgen/deep_atropos/probability_images.nii.gz - -white_stem | \
+testing_diff_image - 5ttgen/deep_atropos/fromprob_whitestem.mif.gz
diff --git a/testing/scripts/tests/5ttgen/deepatropos_fromseg_default b/testing/scripts/tests/5ttgen/deepatropos_fromseg_default
index d8d1133536..e3552a665a 100644
--- a/testing/scripts/tests/5ttgen/deepatropos_fromseg_default
+++ b/testing/scripts/tests/5ttgen/deepatropos_fromseg_default
@@ -2,5 +2,5 @@
 # Verify default operation of "5ttgen deep_atropos"
 #   where input image is the segmentation label image
 # Outcome is compared to that generated using a prior software version
-5ttgen deep_atropos 5ttgen/deep_atropos/segmentation_image.nii.gz tmp.mif -force
-testing_diff_image tmp.mif 5ttgen/deep_atropos/fromseg_default.mif.gz
+5ttgen deep_atropos 5ttgen/deep_atropos/segmentation_image.nii.gz - | \
+testing_diff_image - 5ttgen/deep_atropos/fromseg_default.mif.gz
diff --git a/testing/scripts/tests/5ttgen/deepatropos_fromseg_whitestem b/testing/scripts/tests/5ttgen/deepatropos_fromseg_whitestem
index 5c6994d9a1..242291bd39 100644
--- a/testing/scripts/tests/5ttgen/deepatropos_fromseg_whitestem
+++ b/testing/scripts/tests/5ttgen/deepatropos_fromseg_whitestem
@@ -3,5 +3,5 @@
 #   where input image is the segmentation label image
 #   and the brain stem is allocated to WM rather than 5th volume
 # Outcome is compared to that generated using a prior software version
-5ttgen deep_atropos 5ttgen/deep_atropos/segmentation_image.nii.gz tmp.mif -white_stem -force
-testing_diff_image tmp.mif 5ttgen/deep_atropos/fromseg_whitestem.mif.gz
+5ttgen deep_atropos 5ttgen/deep_atropos/segmentation_image.nii.gz - -white_stem | \
+testing_diff_image - 5ttgen/deep_atropos/fromseg_whitestem.mif.gz
diff --git a/testing/scripts/tests/5ttgen/freesurfer_default b/testing/scripts/tests/5ttgen/freesurfer_default
index c21e4389be..e6a8e2ae7f 100644
--- a/testing/scripts/tests/5ttgen/freesurfer_default
+++ b/testing/scripts/tests/5ttgen/freesurfer_default
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Verify default operation of "5ttgen freesurfer"
 # Outcome is compared to that generated using a prior software version
-5ttgen freesurfer BIDS/sub-01/anat/aparc+aseg.mgz tmp.mif -force
-testing_diff_image tmp.mif 5ttgen/freesurfer/default.mif.gz
+5ttgen freesurfer BIDS/sub-01/anat/aparc+aseg.mgz - | \
+testing_diff_image - 5ttgen/freesurfer/default.mif.gz
diff --git a/testing/scripts/tests/5ttgen/freesurfer_nocrop b/testing/scripts/tests/5ttgen/freesurfer_nocrop
index cebf875a18..3c6dcc2006 100644
--- a/testing/scripts/tests/5ttgen/freesurfer_nocrop
+++ b/testing/scripts/tests/5ttgen/freesurfer_nocrop
@@ -1,4 +1,4 @@
 #!/bin/bash
 # Verify "5ttgen freesurfer" operation when the -nocrop option is specified
-5ttgen freesurfer BIDS/sub-01/anat/aparc+aseg.mgz tmp.mif -nocrop -force
-testing_diff_image tmp.mif 5ttgen/freesurfer/nocrop.mif.gz
+5ttgen freesurfer BIDS/sub-01/anat/aparc+aseg.mgz - -nocrop | \
+testing_diff_image - 5ttgen/freesurfer/nocrop.mif.gz
diff --git a/testing/scripts/tests/5ttgen/freesurfer_sgmamyghipp b/testing/scripts/tests/5ttgen/freesurfer_sgmamyghipp
index b43995d869..a25435f532 100644
--- a/testing/scripts/tests/5ttgen/freesurfer_sgmamyghipp
+++ b/testing/scripts/tests/5ttgen/freesurfer_sgmamyghipp
@@ -1,4 +1,4 @@
 #!/bin/bash
 # Verify "5ttgen freesurfer" operation when the -sgm_amyg_hipp option is specified
-5ttgen freesurfer BIDS/sub-01/anat/aparc+aseg.mgz tmp.mif -sgm_amyg_hipp -force
-testing_diff_image tmp.mif 5ttgen/freesurfer/sgm_amyg_hipp.mif.gz
+5ttgen freesurfer BIDS/sub-01/anat/aparc+aseg.mgz - -sgm_amyg_hipp | \
+testing_diff_image - 5ttgen/freesurfer/sgm_amyg_hipp.mif.gz
diff --git a/testing/scripts/tests/5ttgen/fsl_mask b/testing/scripts/tests/5ttgen/fsl_mask
index b60b724f49..5a8b596f76 100644
--- a/testing/scripts/tests/5ttgen/fsl_mask
+++ b/testing/scripts/tests/5ttgen/fsl_mask
@@ -5,5 +5,5 @@
 #   as such, the slight change in outcomes of the standard_space_roi command
 #   between FSL versions does not affect the outcome of the 5ttgen fsl command.
 #   As such, the outcome can be directly compared to that computed using a prior MRtrix3 version
-5ttgen fsl BIDS/sub-01/anat/sub-01_T1w.nii.gz tmp.mif -mask BIDS/sub-01/anat/sub-01_brainmask.nii.gz -force
-testing_diff_header tmp.mif 5ttgen/fsl/masked.mif.gz
+5ttgen fsl BIDS/sub-01/anat/sub-01_T1w.nii.gz - -mask BIDS/sub-01/anat/sub-01_brainmask.nii.gz | \
+testing_diff_header - 5ttgen/fsl/masked.mif.gz
diff --git a/testing/scripts/tests/5ttgen/fsl_nocrop b/testing/scripts/tests/5ttgen/fsl_nocrop
index dbec9a1997..6e0a742595 100644
--- a/testing/scripts/tests/5ttgen/fsl_nocrop
+++ b/testing/scripts/tests/5ttgen/fsl_nocrop
@@ -1,4 +1,4 @@
 #!/bin/bash
 # Verify "5ttgen fsl" operation when the -nocrop option is specified
-5ttgen fsl BIDS/sub-01/anat/sub-01_T1w.nii.gz tmp.mif -nocrop -force
-testing_diff_header tmp.mif 5ttgen/fsl/nocrop.mif.gz
+5ttgen fsl BIDS/sub-01/anat/sub-01_T1w.nii.gz - -nocrop | \
+testing_diff_header - 5ttgen/fsl/nocrop.mif.gz
diff --git a/testing/scripts/tests/5ttgen/hsvs_aseg b/testing/scripts/tests/5ttgen/hsvs_aseg
index f6a6b402aa..66a0fe9710 100644
--- a/testing/scripts/tests/5ttgen/hsvs_aseg
+++ b/testing/scripts/tests/5ttgen/hsvs_aseg
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Verify "5ttgen hsvs" operation when the segmentation of hippocampi and thalami
 #   are explicitly requested to be pulled from the FreeSurfer aseg image
-5ttgen hsvs freesurfer/sub-01 tmp.mif -hippocampi aseg -thalami aseg -force
-testing_diff_header tmp.mif  5ttgen/hsvs/aseg.mif.gz
+5ttgen hsvs freesurfer/sub-01 - -hippocampi aseg -thalami aseg | \
+testing_diff_header - 5ttgen/hsvs/aseg.mif.gz
diff --git a/testing/scripts/tests/5ttgen/hsvs_default b/testing/scripts/tests/5ttgen/hsvs_default
index 1fc5d04e04..6a0f3e4410 100644
--- a/testing/scripts/tests/5ttgen/hsvs_default
+++ b/testing/scripts/tests/5ttgen/hsvs_default
@@ -1,4 +1,4 @@
 #!/bin/bash
 # Verify "5ttgen hsvs" algorithm under default usage
-5ttgen hsvs freesurfer/sub-01 tmp.mif -force
-testing_diff_header tmp.mif 5ttgen/hsvs/default.mif.gz
+5ttgen hsvs freesurfer/sub-01 - | \
+testing_diff_header - 5ttgen/hsvs/default.mif.gz
diff --git a/testing/scripts/tests/5ttgen/hsvs_first b/testing/scripts/tests/5ttgen/hsvs_first
index d1f9da27b6..de0d5feff2 100644
--- a/testing/scripts/tests/5ttgen/hsvs_first
+++ b/testing/scripts/tests/5ttgen/hsvs_first
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Verify "5ttgen hsvs" operation when the segmentation of hippocampi and thalami
 #   are explicitly requested to be performed using FSL FIRST
-5ttgen hsvs freesurfer/sub-01 tmp.mif -hippocampi first -thalami first -force
-testing_diff_header tmp.mif  5ttgen/hsvs/first.mif.gz
+5ttgen hsvs freesurfer/sub-01 - -hippocampi first -thalami first | \
+testing_diff_header - 5ttgen/hsvs/first.mif.gz
diff --git a/testing/scripts/tests/5ttgen/hsvs_modules b/testing/scripts/tests/5ttgen/hsvs_modules
index 1f3bb2e8e1..efcd656d98 100644
--- a/testing/scripts/tests/5ttgen/hsvs_modules
+++ b/testing/scripts/tests/5ttgen/hsvs_modules
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Verify "5ttgen hsvs" operation when it is explicitly requested that
 #   FreeSurfer sub-cortical gray matter nuclei segmentation modules are utilised
-5ttgen hsvs freesurfer/sub-01 tmp.mif -hippocampi subfields -thalami nuclei -force
-testing_diff_header tmp.mif 5ttgen/hsvs/modules.mif.gz
+5ttgen hsvs freesurfer/sub-01 - -hippocampi subfields -thalami nuclei | \
+testing_diff_header - 5ttgen/hsvs/modules.mif.gz
diff --git a/testing/scripts/tests/5ttgen/hsvs_piping b/testing/scripts/tests/5ttgen/hsvs_piping
deleted file mode 100644
index fdf006e4a2..0000000000
--- a/testing/scripts/tests/5ttgen/hsvs_piping
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-# Ensure correct operation of the "5ttgen hsvs" command
-#   where the output image is sent down a pipe to a subsequent command
-# There is no possibility of input piping to this command
-#   given that the input is a directory rather than an image
-5ttgen hsvs freesurfer/sub-01 - | \
-testing_diff_header - 5ttgen/hsvs/default.mif.gz
diff --git a/testing/scripts/tests/5ttgen/hsvs_template b/testing/scripts/tests/5ttgen/hsvs_template
index 173079119c..2997352274 100644
--- a/testing/scripts/tests/5ttgen/hsvs_template
+++ b/testing/scripts/tests/5ttgen/hsvs_template
@@ -1,4 +1,4 @@
 #!/bin/bash
 # Verify "5ttgen hsvs" operation when the 5TT image is generated on a user-specified template voxel grid
-5ttgen hsvs freesurfer/sub-01 tmp.mif -template BIDS/sub-01/anat/sub-01_T1w.nii.gz -force
-testing_diff_header tmp.mif 5ttgen/hsvs/template.mif.gz
+5ttgen hsvs freesurfer/sub-01 - -template BIDS/sub-01/anat/sub-01_T1w.nii.gz | \
+testing_diff_header - 5ttgen/hsvs/template.mif.gz
diff --git a/testing/scripts/tests/5ttgen/hsvs_whitestem b/testing/scripts/tests/5ttgen/hsvs_whitestem
index 1a76978abb..8e85f71abd 100644
--- a/testing/scripts/tests/5ttgen/hsvs_whitestem
+++ b/testing/scripts/tests/5ttgen/hsvs_whitestem
@@ -1,4 +1,4 @@
 #!/bin/bash
 # Verify "5ttgen hsvs" command when command-line flag "-white_stem" is specified
-5ttgen hsvs freesurfer/sub-01 tmp.mif -white_stem -force
-testing_diff_header tmp.mif 5ttgen/hsvs/white_stem.mif.gz
+5ttgen hsvs freesurfer/sub-01 - -white_stem | \
+testing_diff_header - 5ttgen/hsvs/white_stem.mif.gz
diff --git a/testing/scripts/tests/dwi2mask/legacy_default b/testing/scripts/tests/dwi2mask/legacy_default
index e2c353d851..1a2f7fc051 100644
--- a/testing/scripts/tests/dwi2mask/legacy_default
+++ b/testing/scripts/tests/dwi2mask/legacy_default
@@ -4,7 +4,6 @@
 #   from software versions 3.0.x,
 #   however it is reimplemented in Python
 # The outcome is compared to what was generated from the obsolete C++ binary
-dwi2mask legacy BIDS/sub-01/dwi/sub-01_dwi.nii.gz tmp.mif -force \
--fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval
-
-testing_diff_image tmp.mif dwi2mask/legacy.mif.gz
+dwi2mask legacy BIDS/sub-01/dwi/sub-01_dwi.nii.gz - \
+-fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval | \
+testing_diff_image - dwi2mask/legacy.mif.gz
diff --git a/testing/scripts/tests/dwi2mask/mean_default b/testing/scripts/tests/dwi2mask/mean_default
index d910f87e3e..f0ae126fa4 100644
--- a/testing/scripts/tests/dwi2mask/mean_default
+++ b/testing/scripts/tests/dwi2mask/mean_default
@@ -1,7 +1,6 @@
 #!/bin/bash
 # Verify "dwi2mask mean" algorithm
 #   under default operation
-dwi2mask mean BIDS/sub-01/dwi/sub-01_dwi.nii.gz tmp.mif -force \
--fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval
-
-testing_diff_image tmp.mif dwi2mask/mean.mif.gz
+dwi2mask mean BIDS/sub-01/dwi/sub-01_dwi.nii.gz - \
+-fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval | \
+testing_diff_image - dwi2mask/mean.mif.gz
diff --git a/testing/scripts/tests/dwi2mask/trace_default b/testing/scripts/tests/dwi2mask/trace_default
index 21ec60a6f2..a80a1c722f 100644
--- a/testing/scripts/tests/dwi2mask/trace_default
+++ b/testing/scripts/tests/dwi2mask/trace_default
@@ -1,7 +1,6 @@
 #!/bin/bash
 # Verify result of "dwi2mask trace" algorithm
 #   when executed under default behaviour
-dwi2mask trace BIDS/sub-01/dwi/sub-01_dwi.nii.gz tmp.mif -force \
--fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval
-
-testing_diff_image tmp.mif dwi2mask/trace_default.mif.gz
+dwi2mask trace BIDS/sub-01/dwi/sub-01_dwi.nii.gz - \
+-fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval | \
+testing_diff_image - dwi2mask/trace_default.mif.gz
diff --git a/testing/scripts/tests/dwi2mask/trace_iterative b/testing/scripts/tests/dwi2mask/trace_iterative
index a4ad38fa84..d64c96babb 100644
--- a/testing/scripts/tests/dwi2mask/trace_iterative
+++ b/testing/scripts/tests/dwi2mask/trace_iterative
@@ -1,8 +1,7 @@
 #!/bin/bash
 # Verify result of "dwi2mask trace" algorithm,
 #   when the iterative optimisation algorithm is engaged
-dwi2mask trace BIDS/sub-01/dwi/sub-01_dwi.nii.gz tmp.mif -force \
+dwi2mask trace BIDS/sub-01/dwi/sub-01_dwi.nii.gz - \
 -fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval \
--iterative
-
-testing_diff_image tmp.mif dwi2mask/trace_iterative.mif.gz
+-iterative | \
+testing_diff_image - dwi2mask/trace_iterative.mif.gz
diff --git a/testing/scripts/tests/dwinormalise/manual_percentile b/testing/scripts/tests/dwinormalise/manual_percentile
index a6760d873e..91281f6048 100644
--- a/testing/scripts/tests/dwinormalise/manual_percentile
+++ b/testing/scripts/tests/dwinormalise/manual_percentile
@@ -1,8 +1,7 @@
 #!/bin/bash
 # Test operation of the "dwinormalise manual" algorithm
 #   when the -percentile option is specified to modulate which statistic is used to map to the reference intensity
-dwinormalise manual BIDS/sub-01/dwi/sub-01_dwi.nii.gz BIDS/sub-01/dwi/sub-01_brainmask.nii.gz tmp.mif -force \
+dwinormalise manual BIDS/sub-01/dwi/sub-01_dwi.nii.gz BIDS/sub-01/dwi/sub-01_brainmask.nii.gz - \
 -fslgrad BIDS/sub-01/dwi/sub-01_dwi.bvec BIDS/sub-01/dwi/sub-01_dwi.bval \
--percentile 40
-
-testing_diff_image tmp.mif dwinormalise/manual/percentile.mif.gz -frac 1e-5
+-percentile 40 | \
+testing_diff_image - dwinormalise/manual/percentile.mif.gz -frac 1e-5
diff --git a/testing/scripts/tests/labelsgmfirst/default b/testing/scripts/tests/labelsgmfirst/default
index 88b909700c..3153d215e8 100644
--- a/testing/scripts/tests/labelsgmfirst/default
+++ b/testing/scripts/tests/labelsgmfirst/default
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Verify operation on data where the input parcellation image
 #   already has indices incrementing sequentially from 1
-labelsgmfirst BIDS/sub-01/anat/sub-01_parc-desikan_indices.nii.gz BIDS/sub-01/anat/sub-01_T1w.nii.gz BIDS/parc-desikan_lookup.txt tmp.mif -force
-testing_diff_header tmp.mif labelsgmfirst/default.mif.gz
+labelsgmfirst BIDS/sub-01/anat/sub-01_parc-desikan_indices.nii.gz BIDS/sub-01/anat/sub-01_T1w.nii.gz BIDS/parc-desikan_lookup.txt - | \
+testing_diff_header - labelsgmfirst/default.mif.gz
diff --git a/testing/scripts/tests/labelsgmfirst/freesurfer b/testing/scripts/tests/labelsgmfirst/freesurfer
index 46f024d0fd..35ad9873a3 100644
--- a/testing/scripts/tests/labelsgmfirst/freesurfer
+++ b/testing/scripts/tests/labelsgmfirst/freesurfer
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Verify operation where the input parcellation image comes directly from FreeSurfer,
 #   with parcel indices defined by lookup table FreeSurferColorLUT.txt
-labelsgmfirst BIDS/sub-01/anat/aparc+aseg.mgz BIDS/sub-01/anat/sub-01_T1w.nii.gz labelsgmfirst/FreeSurferColorLUT.txt tmp.mif -force
-testing_diff_header tmp.mif labelsgmfirst/freesurfer.mif.gz
+labelsgmfirst BIDS/sub-01/anat/aparc+aseg.mgz BIDS/sub-01/anat/sub-01_T1w.nii.gz labelsgmfirst/FreeSurferColorLUT.txt - | \
+testing_diff_header - labelsgmfirst/freesurfer.mif.gz
diff --git a/testing/scripts/tests/labelsgmfirst/sgm_amyg_hipp b/testing/scripts/tests/labelsgmfirst/sgm_amyg_hipp
index 3222f29074..3e05dc9b01 100644
--- a/testing/scripts/tests/labelsgmfirst/sgm_amyg_hipp
+++ b/testing/scripts/tests/labelsgmfirst/sgm_amyg_hipp
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Test command execution when the -sgm_amyg_hipp command-line flag is specified,
 #   such that the hippocampi and amygdalae are also substituted with estimates from FSL FIRST
-labelsgmfirst BIDS/sub-01/anat/sub-01_parc-desikan_indices.nii.gz BIDS/sub-01/anat/sub-01_T1w.nii.gz BIDS/parc-desikan_lookup.txt tmp.mif -sgm_amyg_hipp -force
-testing_diff_header tmp.mif labelsgmfirst/sgm_amyg_hipp.mif.gz
+labelsgmfirst BIDS/sub-01/anat/sub-01_parc-desikan_indices.nii.gz BIDS/sub-01/anat/sub-01_T1w.nii.gz BIDS/parc-desikan_lookup.txt - -sgm_amyg_hipp | \
+testing_diff_header - labelsgmfirst/sgm_amyg_hipp.mif.gz
diff --git a/testing/scripts/tests/mask2glass/default b/testing/scripts/tests/mask2glass/default
index a2abd6e71d..0e50a20170 100644
--- a/testing/scripts/tests/mask2glass/default
+++ b/testing/scripts/tests/mask2glass/default
@@ -1,5 +1,5 @@
 #!/bin/bash
 # Verify operation of the "mask2glass" command
 #   under default operation
-mask2glass BIDS/sub-01/dwi/sub-01_brainmask.nii.gz tmp.mif -force
-testing_diff_image tmp.mif mask2glass/out.mif.gz
+mask2glass BIDS/sub-01/dwi/sub-01_brainmask.nii.gz - | \
+testing_diff_image - mask2glass/out.mif.gz
diff --git a/testing/ui_tests/CMakeLists.txt b/testing/ui_tests/CMakeLists.txt
index b761d51ffd..9fc3b86951 100644
--- a/testing/ui_tests/CMakeLists.txt
+++ b/testing/ui_tests/CMakeLists.txt
@@ -39,6 +39,13 @@ dirs_to_unix(EXEC_DIRS "${EXEC_DIRS}")
 include(BashTests)
 function (add_bash_ui_test FILE_SRC)
     get_filename_component(NAME ${FILE_SRC} NAME_WE)
+    # Forward the NO_FILESYSTEM_LOCK opt-out keyword for tests that never write to disk.
+    set(no_filesystem_lock "")
+    foreach(arg ${ARGN})
+        if(arg STREQUAL "NO_FILESYSTEM_LOCK")
+            set(no_filesystem_lock NO_FILESYSTEM_LOCK)
+        endif()
+    endforeach()
     add_bash_test(
         FILE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/${FILE_SRC}"
         PREFIX "uitest"
@@ -46,6 +53,7 @@ function (add_bash_ui_test FILE_SRC)
         EXEC_DIRECTORIES "${EXEC_DIRS}"
         ENVIRONMENT "PYTHONPATH=${PYTHON_ENV_PATH}"
         LABELS "cli;${NAME}"
+        ${no_filesystem_lock}
     )
 endfunction()
 
diff --git a/testing/unit_tests/CMakeLists.txt b/testing/unit_tests/CMakeLists.txt
index 099e87b213..d6bed33905 100644
--- a/testing/unit_tests/CMakeLists.txt
+++ b/testing/unit_tests/CMakeLists.txt
@@ -73,11 +73,19 @@ gtest_discover_tests(mrtrix-unit-tests
 include(BashTests)
 function (add_bash_unit_test FILE_SRC)
     get_filename_component(NAME ${FILE_SRC} NAME_WE)
+    # Forward the NO_FILESYSTEM_LOCK opt-out keyword for tests that never write to disk.
+    set(no_filesystem_lock "")
+    foreach(arg ${ARGN})
+        if(arg STREQUAL "NO_FILESYSTEM_LOCK")
+            set(no_filesystem_lock NO_FILESYSTEM_LOCK)
+        endif()
+    endforeach()
     add_bash_test(
         FILE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/${FILE_SRC}"
         PREFIX "unittest"
         WORKING_DIRECTORY ${DATA_DIR}
         EXEC_DIRECTORIES "${EXEC_DIRS}"
         LABELS "unittest;${NAME}"
+        ${no_filesystem_lock}
     )
 endfunction()