Re: Possible regression in 'wait' command

[Alex fxmbsw7 Ratchev]

https://www.ibm.com/support/pages/exit-code-127-means-jobs-command-can-not-be-found-or-executed

On Thu, May 13, 2021, 23:10 Jonas Alfredsson via Bug reports for the GNU
Bourne Again SHell <bug-bash@gnu.org> wrote:

> Configuration Information:
> Machine: x86_64
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS: -g -O2 -Wno-parentheses -Wno-format-security
> uname output: Linux 5d99d2eaceed 4.19.0-16-amd64 #1 SMP Debian 4.19.181-1
> (2021-03-19) x86_64 GNU/Linux
> Machine Type: x86_64-pc-linux-gnu
> Extra info: Docker version 20.10.6, build 370c289
>
> Bash Version: 5.1
> Patch Level: 0
> Release Status: release
>
> Description:
> If one has a script similar to this:
>
> ```bash
> trap 'echo "Received SIGHUP"' HUP
>
> sleep 5m &
> child_pid=$!
>
> wait -n ${child_pid}
> wait -n ${child_pid}
> ```
>
> and you send in the system signal SIGHUP the first `wait` will exit (as
> expected)
> and the message "Received SIGHUP" will be printed. However, since we have a
> second `wait` it should catch further execution and wait for the child
> once again.
>
> This is how it works in Bash 5.0.x, but on 5.1.0 the second `wait` fails
> with exit
> code 127. Unfortunatly I do not know the low level stuff well enough to
> even
> know where to begin debugging this, but I am willing to help as much as
> possible
> if given a little guidance.
>
> Repeat-By:
> I have created a repository with a Dockerfile and a script that makes this
> repeatable by at least one more person than me. Please check it out for
> more details (or if you want I can include it in a follow up mail if
> requested)
> https://github.com/JonasAlfredsson/bash_fail-to-wait