Here is a scenario:
./configure --prefix=/usr/local/pgsql/9.4.1
make
make install
ln -s 9.4.1 /usr/local/pgsql/9.4
PATH=/usr/local/pgsql/9.4/bin:$PATH
And then when 9.4.2 comes out, the symlink is updated.
I think this sort of setup in variations is not uncommon.
When building other software against that installation, it would use
pg_config --includedir, pg_config --libdir, etc., but that points to
/usr/local/pgsql/9.4.1/lib instead of /usr/local/pgsql/9.4/lib, because
find_my_exec() goes out of its way to resolve symlinks in the returned
path. If the other software saves an rpath or the bindir or something
during the build, then if I later clear out the old 9.4.1 installation,
the other software will break.
The reason for this behavior is
commit 336969e490d71c316a42fabeccda87f798e562dd
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat Nov 6 23:06:29 2004 +0000
Add code to find_my_exec() to resolve a symbolic link down to the actual executable location. This allows people
tocontinue to use setups where, eg, postmaster is symlinked from a convenient place. Per gripe from Josh Berkus.
I don't quite understand what setup Josh was using there.
Is there a way we can consolidate these situations?
