Bug#1027542: epl: FTBFS: make: *** [debian/rules:6: build] Error 25

[David Bremner <david@tethera.net>]

David Bremner <david@tethera.net> writes:

> Adrian Bunk <bunk@debian.org> writes:
>
>>> FTR, the dates when epl started to FTBFS in sid and bookworm are
>>> a good match for when emacs 1:28.2+1-9 entered sid and bookworm:
>>> https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/epl.html
>>
>> Correct link:
>> https://tests.reproducible-builds.org/debian/history/epl.html
>
> Some pretty weird behaviour here
>
> HOME=/n0nexistent emacs -batch -Q -l package \
>   --eval "(add-to-list 'package-directory-list  \"/usr/share/emacs/site-lisp/elpa\")" \
>   --eval "(add-to-list 'package-directory-list  \"/usr/share/emacs/site-lisp/elpa-src\")" \
>   -f package-initialize -L . -L test --eval "(progn (setq comp-enable-subr-trampolines nil) \
>   (load-file \"test/test-helper.el\") (load-file \"test/epl-test.el\"))" \
>   -l test/epl-test.el --eval \(ert-run-tests-batch-and-exit\)
>
> fails, but replacing /n0nexistent with /nonexistent passes. I hope this is not a sign that someone has special cased /nonexistent, but I fear otherwise.

This weird behaviour is a consequence of emacs' ill-advised
special-casing of "HOME==/nonexistent" in startup.el (around line 550).

if HOME==/nonexistent, then emacs tries to provide a temporary directory
for native compilation output. Why this is needed is a different question.