Emacs28 / flycheck is spawning wild running shellcheck processes eating up the system memory (oom-kill)

[DirkSchmitt]

Bug description

The combination of Emacs28 + elpa-flycheck + shellcheck in bookworm spawn never terminating shellcheck processes.
These are eating up the memory and trigger oom-kill.

This renders my system unstable. It appears to be blocked minutes till the oem-kill cleans up some memory.

Analysis

I have temporarly downgraded elpa-flycheck and shellcheck. The wild processes are still spawned.
So I assume that Emacs28 introduce a different behaviour here that is probematic for flycheck or shellcheck.

Mitigation

As a mitigation I exclude the invocation of shellcheck in my Emacs setup:
(customize-set-variable 'flycheck-disabled-checkers '(sh-shellcheck))

System Configuration

As reported by dpkg -l:

ii elpa-flycheck 32~git.20200527.9c435db3-3 all modern on-the-fly syntax checking for Emacs
ii emacs 1:28.2+1-13 all GNU Emacs editor (metapackage)
ii shellcheck 0.9.0-1 amd64 lint tool for shell scripts

Also reported to Debian:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1033655