bug#51110: Native-comp leaks fds open on /dev/ptmx

[Stephen Gildea]

Version: 28.0.60
Severity: important

Native-comp leaks fds open on /dev/ptmx if you change 'invocation-name'
and then run a function that loads libraries and causes some compilation.
Emacs seems to compile each file multiple times (16 or more), and it soon
runs out of file descriptors.

To reproduce:

Use a newly built (configure --with-native-compilation) Emacs that has
never (successfully) run MH-E before; if your eln-cache has already been
populated, you will need to delete the cache to repeat the failure:

rm -r ~/.emacs.d/eln-cache

The Emacs must be interactive, and you can reproduce quickly as follows:

src/emacs -Q --eval '(setq invocation-name "emacs-leaks")' --eval '(mh-version)'

In a few seconds the echo area will say: "Creating pipe: Too many open files"

What should appear in the echo area: "nmh 1.7.1 installed as MH variant"
or maybe: "No MH variant found on the system"