We configure Postgres with --disable-rpath because for the most part we

want to leave it to ldconfig to determine where libraries are.  However,

for some reason the Perl package puts libperl.so in a nonstandard place

and doesn't add that place to the ldconfig search path.  I think this

is a Perl packaging bug, myself, but apparently it's not going to change.

So work around it by adding an rpath spec to plperl.so (only).

Per bug #162198.

diff -up postgresql-12beta2/src/pl/plperl/GNUmakefile.p3 postgresql-12beta2/src/pl/plperl/GNUmakefile

--- postgresql-12beta2/src/pl/plperl/GNUmakefile.p3	2019-07-26 15:28:50.210984029 +0200

+++ postgresql-12beta2/src/pl/plperl/GNUmakefile	2019-07-26 15:29:38.504501120 +0200

@@ -55,6 +55,9 @@ endif # win32

 SHLIB_LINK = $(perl_embed_ldflags)

+# Force rpath to be used even though we disable it everywhere else

+SHLIB_LINK += $(rpath)

+

 REGRESS_OPTS = --dbname=$(PL_TESTDB) --load-extension=plperl  --load-extension=plperlu

 REGRESS = plperl plperl_lc plperl_trigger plperl_shared plperl_elog plperl_util plperl_init plperlu plperl_array plperl_call plperl_transaction

 # if Perl can support two interpreters in one backend,