On 7/13/25 12:37 PM, John Sidles wrote:
Bash Version: 5.3 Patch Level: 0 Release Status: releaseDescription: MacOS Homebrew bash '5.3.0(1)-release' (apparently?) breaks 'wait' bash-settings are as follows (in my experiments, the sole critical setting is "posix on")
Repeat-By: # SUMMARY: the following three commands # minimally elicit a failure-to-wait bug set -o posix ; mapfile -t JOBS < <(jobs -rp); sleep 10 & wait -f -n $! ; # FAILURE: 'wait' DOES NOT WAIT
It does wait, and returns a status, it just isn't waiting for the process you think it is. This was the result of a *long* (months-long) 2024 discussion in bug-bash. Here are some threads from each month that capture the discussion: https://lists.gnu.org/archive/html/bug-bash/2024-06/msg00213.html https://lists.gnu.org/archive/html/bug-bash/2024-07/msg00013.html https://lists.gnu.org/archive/html/bug-bash/2024-08/msg00054.html https://lists.gnu.org/archive/html/bug-bash/2024-09/msg00007.html https://lists.gnu.org/archive/html/bug-bash/2024-10/msg00068.html The short story is that `wait -n' now returns the status of any process that's completed and hasn't been waited for yet, just like `wait'. It's not restricted to processes that terminates after it's invoked. It does this even when it's given a list of pid or job arguments, which is where the problem here arises. That's probably not what I intended with the change in the first place, but it was a fast-moving target. The fix for your case is to insert `wait' without arguments after the call to mapfile aned before the sleep. That way you ensure that the `wait -n' waits for the sleep process. In fact, your script above doesn't need `wait -n' at all; it can use `wait'. If you'd like to play around with the source code, here's a patch that restores the bash-5.2 behavior for `wait -n' with pid arguments. Chet -- ``The lyf so short, the craft so long to lerne.'' - Chaucer ``Ars longa, vita brevis'' - Hippocrates Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/
*** ../bash-5.3/jobs.c Fri Mar 7 18:48:44 2025
--- jobs.c Mon Jul 14 10:25:13 2025
***************
*** 3539,3543 ****
one in bgpids. We can do this in posix mode because we'll remove any
one we find from the table, preserving existing semantics. */
! if (posixly_correct && (t = bgp_findone ()))
{
pid = t->pid;
--- 3539,3543 ----
one in bgpids. We can do this in posix mode because we'll remove any
one we find from the table, preserving existing semantics. */
! if (posixly_correct && (flags & JWAIT_WAITING) == 0 && (t = bgp_findone ()))
{
pid = t->pid;
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