play-with-mpv: unstable-2020-05-18 -> unstable-2021-04-02

[tjni]

Description of changes

I took the opportunity to update this package a few more commits:

https://github.com/Thann/play-with-mpv/commits/master

But the main motivation is that some changes I am making to Python bootstrapping are revealing missing dependencies that were being silently ignored before. (I think pip was being used to attempt to download them, and then the build continued afterward when that download fails.)

Here, the main change is that the custom build of install-freedesktop needs to be an actual Python package in order for setuptools to recognize that it's a fulfilled dependency.

We can also get rid of the git dependency if we replace the version in setup.py with a valid version string.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.11 Release Notes (or backporting 23.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.