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

[Eli Zaretskii]

> From: Bhavin Gandhi <bhavin7392@gmail.com>
> Date: Sat, 1 Jan 2022 22:42:08 +0530
> Cc: 52376@debbugs.gnu.org, akrl@sdf.org
> 
> When all three variants are built, the make install is run from
> build-gtk directory at the end. And during this install command, it is
> creating a emacs.pdmp again, where build says Loading foo only.
> 
> Can be reproduced with following commands:
> 
> mkdir build-gtk
> cd build-gtk/
> ln -s ../configure .
> ./configure <for GTK>
> make bootstrap
> make
> cd ..
> 
> mkdir build-nox
> cd build-nox/
> ln -s ../configure .
> ./configure <for No-X>
> make bootstrap
> make
> 
> cd ../build-gtk
> sudo make install
> ^^^ This runs configure, make all lib etc again, I can see a new
> emacs.pdmp file being created which loads foo.el from source.
> 
> Is this type of build and install flow supported?

I don't know yet.  The root cause is probably something that causes a
complete rebuild in the build-gtk tree when you say "make install",
although you already built it before.  Can you figure out why it
rebuilds it?  Then we can reason about that cause, whether it's
expected or not.