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

[Eli Zaretskii <eliz@gnu.org>]

> From: Bhavin Gandhi <bhavin7392@gmail.com>
> Date: Wed, 8 Dec 2021 22:51:14 +0530
> 
> I have been trying to build a RPM package for pretest 28.0.90. This
> process builds three variants, GTK3, Lucid, and No X.

Please describe in more detail how you build the 3 versions.  Are you
using the same source tree, but different build directories, for
example?  Do you clean up the tree between different builds?

> When I install and start GTK3 based Emacs with emacs -Q, the value of
> native-comp-eln-load-path does not have
> /usr/lib64/emacs/28.0.90/native-lisp/ in it.
> 
> --8<---------------cut here---------------start------------->8---
> native-comp-eln-load-path is a variable defined in ‘C source code’.
> 
> Its value is
> ("/home/bhavin/.emacs.d/eln-cache/" "/home/bhavin/src/emacs/native-lisp/")
> --8<---------------cut here---------------end--------------->8---

This is normal if you start Emacs from the build tree.  is that what
you did?

> $ ls -ll /usr/lib64/emacs/28.0.90/native-lisp/28.0.90-619a407c/
> total 3080
> -rw-r--r--. 1 root root  81216 Dec  8 15:14 autoload-f3599901-fca77eea.eln
> …

Was this directory produced by "make install" from the same build
that built the GTK3 version?  The *.eln files are specific to the
binary with which they were produced, so the fact that you have the
*.eln files there doesn't yet mean that a specific Emacs binary will
accept them as matching the binary.

> To isolate the issue I tried following commands with newly extracted
> pretest tar:
> 
> 
> --8<---------------cut here---------------start------------->8---
> $ ./configure --build=x86_64-redhat-linux-gnu
> --host=x86_64-redhat-linux-gnu --program-prefix=
> --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr
> --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc
> --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64
> --libexecdir=/usr/libexec --localstatedir=/var
> --sharedstatedir=/var/lib --mandir=/usr/share/man
> --infodir=/usr/share/info --with-dbus --with-gif --with-jpeg
> --with-png --with-rsvg --with-tiff --with-xft --with-xpm
> --with-x-toolkit=gtk3 --with-gpm=no --with-xwidgets --with-modules
> --with-harfbuzz --with-cairo --with-json --with-native-compilation
> $ make -j8 bootstrap
> $ make -j8
> $ sudo make -j8 install

How is this different from the commands you used to produce the build
which didn't find the *.eln files?