execute_sql hangs forever until you call .rows on the results

[grcooper]

Problem

When calling execute_sql the program hangs forever (I had to kill -9 it) unless you read from .rows.

Environment details

• OS: MacOS
• Ruby version: 3.4.2
• Gem name and version: google-cloud-spanner 2.26

Steps to reproduce

1. Create a client
2. client.execute_sql
3. Never read the result from execute_sql
4. Program hangs forever

Code example

require "google/cloud/spanner"

puts "Starting"
emulator_host = ENV.fetch("SPANNER_EMULATOR_HOST", nil)
project_id = ENV.fetch("SPANNER_EMULATOR_PROJECT", "")
instance_id = ENV.fetch("SPANNER_EMULATOR_INSTANCE", "")
database_id = ENV.fetch("SPANNER_EMULATOR_DATABASE", "")

puts "Creating project"
project = Google::Cloud::Spanner.new(
  project_id: project_id,
  emulator_host: emulator_host,
)

puts "Creating client"
client = project.client(instance_id, database_id)

puts "Executing sql"
puts client.execute_sql("SELECT * FROM my_table")

Change the last line to:

puts client.execute_sql("SELECT * FROM my_table").rows.first

And it will no longer hang.

Full backtrace

There is no backtrace, the program just hangs forever after printing "Executing sql"