Like you, I can't reproduce it on the desktop platforms I have available right now.
The bash devel git branch has fairly fine granularity. If you can automate the signal sending somewhat, maybe by having a child process send signals to $$, you could use your script and `git bisect' to find the commit where the behavior changed. bash-5.0 was frozen 12/31/2018, and bash-5.1 was frozen 12/14/2020, so that should get you started with the devel branch commits you want to inspect. http://git.savannah.gnu.org/cgit/bash.git/log/?h=devel I have found the commit on devel branch which breaks things for me (and probably other Yocto-based builds): This one still works ====================== commit 89d788fb0152724a93e0fdab8c15116e5c76572b Author: Chet Ramey <chet.ra...@case.edu> Date: Mon Feb 17 11:41:35 2020 -0500 commit bash-20200214 snapshot This one not ====================== commit 0df4ddca3f371bc258fe4185cdec36fce3e7be7b Author: Chet Ramey <chet.ra...@case.edu> Date: Mon Feb 24 10:41:37 2020 -0500 commit bash-20200221 snapshot Please take a look. Maybe you'll notice something suspicious there. I don't know... uninitialized variables, endian-dependent code, etc. Thank you, Mykyta