trapme: Xvfb startup timeout not obvious in logs

[sxa]

This is something I'm sure I've hit before (or certainly similar problems) but I don't think we've addressed it, so I'm raising an issue so it doesn't get lost. I've added trapme to the title so I can track any improvements to error conditions.

In https://ci.adoptium.net/job/Test_openjdk21_hs_sanity.openjdk_riscv64_linux/108/console we hit an issue where, for no clear reason, the tests didn't seem to start running. @sophia-guo spotted that it might be an issue with the Xvfb startup. Here is the log from a failing run:

8:54:41  ITERATION: 1/1
[Pipeline] wrap
18:54:41  $ Xvfb -displayfd 2 -screen 0 1024x768x24 -fbdir /home/jenkins/workspace/Test_openjdk21_hs_sanity.openjdk_riscv64_linux/.xvfb-108-..fbdir4921422941276978355
[Pipeline] // wrap
[Pipeline] }
[Pipeline] // stage
[Pipeline] stage
[Pipeline] { (Post)
[Pipeline] step
18:55:21  TAP Reports Processing: START
18:55:21  Looking for TAP results report in workspace using pattern: aqa-tests/TKG/**/*.tap
18:55:21  Did not find any matching files. Setting build result to FAILURE.

And this is from a good run of the same thing on another machine:

10:04:20  ITERATION: 1/1
[Pipeline] wrap
10:04:20  $ Xvfb -displayfd 2 -screen 0 1024x768x24 -fbdir /home/jenkins/workspace/Test_openjdk21_hs_sanity.openjdk_riscv64_linux/.xvfb-115-..fbdir4816611008607352758
[Pipeline] {
[Pipeline] sh
10:04:32  + ps -f
10:04:32  + awk {print $9}
10:04:32  + grep [X]vfb
[Pipeline] echo
10:04:32  env.DISPLAY is :0

Ideally we should have something showing in the log to indicate that a timeout occurred (if indeed it can be confirmed that it is the cause of the failure)

[adamfarley]

This issue (or something that looks like it) is still happening. Examples include these two test jobs on JDK11 for pLinux: Sanity.functional and Sanity.openjdk.

23:02:55  Running tests...
[Pipeline] echo
23:02:55  ITERATION: 1/1
[Pipeline] wrap
23:02:56  $ Xvfb -displayfd 2 -screen 0 1024x768x24 -fbdir /home/jenkins/workspace/Test_openjdk11_hs_sanity.openjdk_ppc64le_linux_testList_0/.xvfb-5-..fbdir13841752235363429749
[Pipeline] // wrap
[Pipeline] }
[Pipeline] // stage
[Pipeline] stage
[Pipeline] { (Post)
[Pipeline] step
23:03:47  TAP Reports Processing: START
23:03:47  Looking for TAP results report in workspace using pattern: aqa-tests/TKG/**/*.tap
23:03:56  Did not find any matching files. Setting build result to FAILURE.

Machines are test-docker-ubuntu2004-ppc64le-1 and test-docker-fedora39-ppc64le-1 respectively.