bug#52376: 28.0.90; libdir is missing from native-comp-eln-load-path with GTK3 build

[Bhavin Gandhi]

Hello Eli and Andrea

On Thu, 9 Dec 2021 at 16:36, Andrea Corallo <akrl@sdf.org> wrote:
> eln files are most likely not sharable between these two builds, copying
> them will have no effect as Emacs will decide not use them.
>
> eln files should be produced for each flavour of build independently.

Yes, I'm keeping them for each build independently, the three
directories below are for GTK3, Lucid, and no-X

$ ls /usr/lib64/emacs/28.0.90/native-lisp/
28.0.90-619a407c  28.0.90-a325c617  28.0.90-f21cc02e

On Thu, 9 Dec 2021 at 02:01, Bhavin Gandhi <bhavin7392@gmail.com> wrote:
> > I suggest to step in a debugger through the
> > code in load_pdump, and see which of the *.pdmp files it finds in the
> > problematic case; my guess is that it finds the one in the build
> > directory, not in the installation directory.
>
> Okay. I will try to do that and see what it shows.
> […]
> Thank you for the help so far. I will experiment and post results here.

So, I build the binaries again as suggested by etc/DEBUG, set breakpoint
at load_pdump function. Here is the command log and output values I got.

--8<---------------cut here---------------start------------->8---
bhavin@toolbox ~ $ gdb  --args /usr/bin/emacs -Q
Reading symbols from /usr/bin/emacs...
Reading symbols from
/usr/lib/debug/usr/bin/emacs-28.0.90-28.0.90-1.fc35.x86_64.debug...
(gdb) directory
/home/bhavin/src/emacs/emacs-pretest-rpm/emacs-28.0.90/build-gtk/src
Source directories searched:
/home/bhavin/src/emacs/emacs-pretest-rpm/emacs-28.0.90/build-gtk/src:$cdir:$cwd
(gdb) source 
/home/bhavin/src/emacs/emacs-pretest-rpm/emacs-28.0.90/build-gtk/src/.gdbinit
Warning: /home/bhavin/../lwlib: No such file or directory.
SIGINT is used by the debugger.
Are you sure you want to change it? (y or n) [answered Y; input not
from terminal]
DISPLAY = :0
TERM = xterm-256color
Breakpoint 1 at 0x5d58c0: file ../../src/emacs.c, line 399.
Breakpoint 2 at 0x592bad: file ../../src/xterm.c, line 10252.

(gdb) break load_pdump
Breakpoint 3 at 0x5d6679: file ../../src/emacs.c, line 829.

(gdb) run
Starting program: /usr/bin/emacs -Q

Breakpoint 3, load_pdump (argc=2, argv=0x7fffffffe1b8) at ../../src/emacs.c:829
829    {

I pressed n a couple of times here.

871      emacs_executable = load_pdump_find_executable (argv[0], &bufsize);
(gdb)
872      exec_bufsize = bufsize;

(gdb) p emacs_executable
$1 = 0xdf0190 "/usr/bin/emacs-28.0.90"

(gdb)
909      result = pdumper_load (dump_file, emacs_executable);
(gdb) p dump_file
$2 = 0xd99900 "/usr/bin/emacs-28.0.90.pdmp"

(gdb) n
910      if (result == PDUMPER_LOAD_SUCCESS)
(gdb) p result
$3 = 0
(gdb) c
Continuing.
--8<---------------cut here---------------start------------->8---

So, I think it is able to find the correct .pdmp file in this case, but
when I continue and inspect native-comp-eln-load-path, the libdir is
still not there.

In case of Lucid, it finds the /usr/bin/emacs-28.0.90-lucid.pdmp, and
when continuing the libdir is there is native-comp-eln-load-path.