Zlib 1.2.12 built with GCC without CC-logic in configure patch misses ZLIB_1.2.x symbols

[robert-mijakovic]

This is just to document the issue I faced when I tried to build zlib 1.2.12 without CC-login patch for configure script.

I compiled ZLib 1.2.12 using GCC 10.4.0 but forgot to patch it with a CC-login in configure script patch.
zlib builds and generates the shared object which does not have ZLIB_1.2.x symbols.
Consequently, packages that use zlib will fail with libz.so.1: version 'ZLIB_1.2.0\' not found (required by python)\n').

When I investigated the issue, I tried to grep for symbols and they were missing.

$ strings zlib/1.2.12-GCCcore-10.4.0/lib/libz.so.1 | grep ZLIB

Normally, the linker would fail with bad value, as reported by Gentoo, but this is somehow circumvented by fPIC flag that EasyBuild uses.

When the patch is applied:

$ strings zlib/1.2.12-GCCcore-10.4.0/lib/libz.so.1 | grep ZLIB
ZLIB_1.2.0
ZLIB_1.2.0.2
ZLIB_1.2.0.8
ZLIB_1.2.2
ZLIB_1.2.2.3
ZLIB_1.2.2.4
ZLIB_1.2.3.3
ZLIB_1.2.3.4
ZLIB_1.2.3.5
ZLIB_1.2.5.1
ZLIB_1.2.5.2
ZLIB_1.2.7.1
ZLIB_1.2.9
ZLIB_1.2.12
...

[robert-mijakovic]

Closing as this is just to document the issue.