runscript does not pass signals (e.g. SIGINT) to forked processes as it did in version 2

[lparsons]

Version of Singularity:

3.0.3

Expected behavior

Signals (e.g. SIGINT) are passed from the runscript to the forked process being executed.

Actual behavior

Signals are not passed to forked processes since the runscript uses eval to execute the command. In earlier versions (version 2.x) it used exec which meant that signals made it to the new process.

Steps to reproduce behavior

1. Pull docker container
2. Issue command using singularity run container.img COMMAND_LISTENING_FOR_SIGINT
3. Send SIGINT to the child process created in 2.

There is an example of this problem documented in ComparativeGenomicsToolkit/cactus#60.

Another somewhat related issues was #2622, although that was regarding quoting of parameters.

[cclerget]

Hi @lparsons, current master branch should fix this issue

[mem]

The issue is related to this #3696? (I could not find another commit that deals with signals, and given @cclerget comment above, I don't think #3696 is the right one given the timestamp).

[cclerget]

Closing, fixed by #2552