I get this Python error while trying to run a project:

Traceback (most recent call last):
[...]
  File "/nix/store/xprlxxzf2h78n7p2hss7mch55bnqvjgh-python3.11-gradio-3.44.3/lib/python3.11/site-packages/gradio/utils.py", line 38, in <module>
    import matplotlib
  File "/nix/store/q556sbzkyn1jawipz0mqxv5qs0fr01jc-python3.11-matplotlib-3.8.0/lib/python3.11/site-packages/matplotlib/__init__.py", line 259, in <module>
    _check_versions()
  File "/nix/store/q556sbzkyn1jawipz0mqxv5qs0fr01jc-python3.11-matplotlib-3.8.0/lib/python3.11/site-packages/matplotlib/__init__.py", line 244, in _check_versions
    from . import ft2font
ImportError: /nix/store/k8yhrp77shpwcwwlqqdfjsq297p9jxjl-libz-unstable-2018-03-31/lib/libz.so.1: version `ZLIB_1.2.9' not found (required by /nix/store/v8jrcx5r8j74wkb6q3qfv73aizl8vl3z-libpng-apng-1.6.40/lib/libpng16.so.16)
Apparently, libz 1.2.9 is needed, but there’s only version 1.2.8:
$ ls /nix/store/k8yhrp77shpwcwwlqqdfjsq297p9jxjl-libz-unstable-2018-03-31/lib/
libz.so  libz.so.1  libz.so.1.2.8
Why is the wrong dependency linked? How can I provide version 1.2.9?
Context:
I’m trying to get Stable Diffusion to run on my computer with NixOS. The current state of local text-to-image AIs seem to be very broken. I’ve been expecting to just apply band-aids while stumbling from error to error.
But for this error, the last line (about ZLIB_1.2.9 not being found but required by libpng) made me think it might be nix’s fault, not pythons.
If you need any more info, I’m happy to provide, I just didn’t know what would be useful, I’m kinda new and inexperienced with nix.
              
I now downloaded the zlib 1.2.9 source tarball and compiled it and put the 1.2.9 library at the start of $LD_LIBRARY_PATH. That worked.
Should I sumbit a bug report for libpng-apng?
What disturbs me is that in nixpkgs/pkgs/development/libraries/libpng/default.nix at 809cca784b9f72a5ad4b991e0e7bcf8890f9c3a6 · NixOS/nixpkgs · GitHub uses zlib from top-level, and this zlib is runnig version 1.3, so more modern that your own version: NixOS Search So maybe explaining how you get this environment could help here.
(btw, libz is not exactly like zlib, you seem to mention both)