Multi-threaded build fails with VCS

[benoitdenkinger]

Problem

When running the build command with make using multiple threads, the build fails for VCS. For example, in the simple_verilog example doing make run_tb_vcs -j2 fails while make run_tb_vcs succeed.

Setup

• OS: "Red Hat Enterprise Linux release 8.10 (Ootpa)"
• CMake version: 3.28.4
• GCC version: 8

[Risto97]

Hello Benoit,
I don't see this issue on neither master nor develop.

Can you attach the error report to try to undestand where the issue might be

[mtravaillard]

Hi @Risto97 and @benoitdenkinger,

I have been experiencing the same problem with different versions of VCS...

It seems that it's a problem due to the parallelization, maybe adding BUILD_JOB_SERVER_AWARE like in the commits faacc98 would help the generated Makefile to correctly build everything. This would require cmake 3.28+...

I don't think I can share a lot, but in case that can help, I get the following error in my shell that happens during the elaboration:

make[5]: *** read jobs pipe: Bad file descriptor.  Stop.
make[5]: *** Waiting for unfinished jobs....
make[4]: *** [Makefile:115: XXXXXXXXXXXX] Error 2
Make exited with status 2

Before this, there is apparently a segfault, which should not cause any problem as it also happens and works when not using -j2 and there is also 1 or 2 make on the stack between this and the problem with the jobs pipe.

Hope this can help to understand my problem, for now, I deactivated the multi-thread build when using VCS in my script.

[Risto97]

I can' replicate it on my setups.
I tested on Redhat 8.10, and VCS 2025, and 2 version of 2023.
Also on Redhat 7, and some older VCS version.

Before this, there is apparently a segfault, which should not cause any problem as it also happens and works when not using -j2 and there is also 1 or 2 make on the stack between this and the problem with the jobs pipe.

This is concerning, but we cannot exclude that there is a problem with the VCS installation on your setup.
Maybe you can check if the LD_LIBRARY_PATH is modified, try to isolate VCS maybe when trying this test, and exclude any other simulators and tools from the environment.