guile-zlib: fix path to zlib

[ghpzin]

• add patch changing path to libz.so from libdir to sharedlibdir
  variable from zlib.pc

In guile-zlib default way of finding libz.so is to load zlib.pc
with PKG_CHECK_MODULES macro and take path from libdir variable
inside.

After change in:
#476830
ff59162
libdir variable in zlib.pc points to zlib.static, so only libz.a
is there.
Add patch fixing configure.ac to load path from sharedlibdir instead.

Fixes build failure of guile-zlib:

make  check-TESTS
make[1]: Entering directory '/build/source'
make[2]: Entering directory '/build/source'
make[2]: *** [Makefile:873: tests/zlib.log] Error 1
make[2]: Leaving directory '/build/source'
make[1]: *** [Makefile:856: check-TESTS] Error 2
make[1]: Leaving directory '/build/source'
make: *** [Makefile:1059: check-am] Error 2

zlib.log:

Backtrace:
          19 (primitive-load-path "tests/zlib.scm")
...
In unknown file:
           2 (primitive-load-path "zlib" #<procedure 7fffeee418c0 at
ice-9/boot-9.scm:3603:37 ()>)
In zlib.scm:
   486:25  1 (_)
   486:25  0 (_)

zlib.scm:486:25: Wrong type to apply: #f

---

See comments in #494567 for extra context.

Fixes #493503

Things done

• Built on platform:
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• Tested, as applicable:
  • NixOS tests in nixos/tests.
  • Package tests at passthru.tests.
  • Tests in lib/tests or pkgs/test for functions and "core" functionality.
• Ran nixpkgs-review on this PR. See nixpkgs-review usage.
• Tested basic functionality of all binary files, usually in ./result/bin/.
• Nixpkgs Release Notes
  • Package update: when the change is major or breaking.
• NixOS Release Notes
  • Module addition: when adding a new NixOS module.
  • Module update: when the change is significant.
• Fits CONTRIBUTING.md, pkgs/README.md, maintainers/README.md and other READMEs.

[marcin-serwin]

If they expect shared objects in libdir then I'd argue it's an upstream bug and it would be preferable to send them a patch like this one:

diff --git a/configure.ac b/configure.ac
index dc2534d..dc5726e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -30,7 +30,7 @@ fi
 
 PKG_CHECK_MODULES([LIBZ], [zlib])
 AC_MSG_CHECKING([libz library directory])
-PKG_CHECK_VAR([LIBZ_LIBDIR], [zlib], [libdir])
+PKG_CHECK_VAR([LIBZ_LIBDIR], [zlib], [sharedlibdir])
 AC_MSG_RESULT([$LIBZ_LIBDIR])
 AS_IF([test "x$LIBZ_LIBDIR" = "x"], [
   AC_MSG_FAILURE([Unable to identify libz lib path.])

[ghpzin]

Unfortunately upstream repo is gone (at least temporarily):
https://notabug.org/guile-zlib/guile-zlib -- returns 404

Main instance - https://notabug.org says:

Due to relentless AI scrapers notabug.org is currently down.
We are attempting to come up with a solution to this problem.

I can convert to patch if that is preferable (so it may be submitted upstream someday).

[ghpzin]

nixpkgs-review result

Generated using nixpkgs-review.

Command: nixpkgs-review pr 497498
Commit: 682ba25a29558983ba7196eb95c7f700959d0061

---

x86_64-linux

✅ 2 packages built:

• guile-zlib
• guix