$ git submodule update --init --recursive
...
Submodule path 'thirdparty/qt-tuio-sender': checked out 'a2aff58240cd7aad6be7a4553fe93748759ed63c'
Submodule 'TUIO20_CPP' (git@github.com:mkalten/TUIO20_CPP.git) registered for path 'thirdparty/qt-tuio-sender/TUIO20_CPP'
Cloning into '/home/user/git/grefsen/thirdparty/qt-tuio-sender/TUIO20_CPP'...
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'git@github.com:mkalten/TUIO20_CPP.git' into submodule path '/home/user/git/grefsen/thirdparty/qt-tuio-sender/TUIO20_CPP' failed
Failed to clone 'TUIO20_CPP'. Retry scheduled
Cloning into '/home/user/git/grefsen/thirdparty/qt-tuio-sender/TUIO20_CPP'...
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
fatal: clone of 'git@github.com:mkalten/TUIO20_CPP.git' into submodule path '/home/user/git/grefsen/thirdparty/qt-tuio-sender/TUIO20_CPP' failed
Failed to clone 'TUIO20_CPP' a second time, aborting
fatal: Failed to recurse into submodule path 'thirdparty/qt-tuio-sender'
