bug#64226: 30.0.50; emacs-lisp-native-compile-and-load permission error

[Andrea Corallo <acorallo@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: No Wayman <iarchivedmywholelife@gmail.com>
>> Cc: Andrea Corallo <acorallo@gnu.org>, 64226@debbugs.gnu.org
>> Date: Thu, 22 Jun 2023 11:44:33 -0400
>> 
>> I have reproduced from emacs -Q as well. Same error as above:
>> 
>> 
>> Compiling /home/n/.emacs.d/elpaca/repos/elpaca/elpaca.el...done
>> comp--native-compile: Native compiler error: 
>> "/home/n/.emacs.d/elpaca/repos/elpaca/elpaca.el", "Compiling 
>> /usr/lib/emacs/30.0.50/native-lisp/30.0.50-58a66af6/elpaca-0646d6fc-1256ece5.eln...
>> Creating file with prefix: Permission denied, 
>> /usr/lib/emacs/30.0.50/native-lisp/30.0.50-58a66af6/elpaca-0646d6fc-1256ece5
>> 
>> Error: permission-denied (\"Creating file with prefix\" 
>> \"Permission denied\" 
>> \"/usr/lib/emacs/30.0.50/native-lisp/30.0.50-58a66af6/elpaca-0646d6fc-1256ece5\")
>>   mapbacktrace(#f(compiled-function (evald func args flags) 
>>   #<bytecode 0x70d6f07f3ae8645>))
>>   debug-early-backtrace()
>>   debug-early(error (permission-denied \"Creating file with 
>>   prefix\" \"Permission denied\" 
>>   \"/usr/lib/emacs/30.0.50/native-lisp/30.0.50-58a66af6/elpaca-0646d6fc-1256ece5\"))
>>   make-temp-file(\"/usr/lib/emacs/30.0.50/native-lisp/30.0.50-58a66af6/elpaca-0646d6fc-1256ece5\" 
>>   nil \".eln.tmp\" nil)
>>   comp--compile-ctxt-to-file(\"/usr/lib/emacs/30.0.50/native-lisp/30.0.50-58a66af6/elpaca-0646d6fc-1256ece5.eln\")
>>   comp-compile-ctxt-to-file(\"/usr/lib/emacs/30.0.50/native-lisp/30.0.50-58a66af6/elpaca-0646d6fc-1256ece5.eln\")
>>   comp-final1()
>>   load-with-code-conversion(\"/tmp/emacs-int-comp-elpaca-0646d6fc-1256ece5-oSdhiB.el\" 
>>   \"/tmp/emacs-int-comp-elpaca-0646d6fc-1256ece5-oSdhiB.el\" nil 
>>   t)
>>   command-line-1((\"-l\" 
>>   \"/tmp/emacs-int-comp-elpaca-0646d6fc-1256ece5-oSdhiB.el\"))
>>   command-line()
>>   normal-top-level()
>>  
>> > I also don't understand why the backtrace above seems to imply 
>> > that
>> > you invoked Emacs like this:
>> >
>> >   emacs -l 
>> >   /tmp/emacs-int-comp-elpaca-0646d6fc-1256ece5-73Dpd0.el
>> 
>> > IOW, the backtrace doesn't show invocation of
>> > emacs-lisp-native-compile-and-load, it shows the attempt to load 
>> > an
>> > already-compiled .eln file.  What am I missing?  I added Andrea 
>> > to
>> > this discussion.
>> 
>> The compilation takes place in a subprocess, no?
>
> No, I don't think so, not with emacs-lisp-native-compile-and-load.
> Andrea, am I right?

We always invoke libgccjit in a subprocess, the difference between sync
and async is:

- in sync compilation we run all our compiler *but* libgccjit in process
  (libgccjit runs in a subprocess)

- in async all the compilation computation is done in a sub process.

The reason for running libgccjit always in a subprocess is that
unfortunatelly it leaks memory.

Best Regards

  Andrea