Motivation for this change

Previously Bokeh would build and pass tests, but import bokeh.plotting would fail with

  File "/nix/store/d7rlq9db362d9zgvrd0rb9x0bhzp0p03-python3.7-bokeh-1.3.4/lib/python3.7/site-packages/bokeh/util/dependencies.py", line 28, in <module>
    from packaging.version import Version as V
ModuleNotFoundError: No module named 'packaging'

Note that packaging is in Bokeh's requirements, and here is the commit that introduced it.

Things done

Just added packaging to propagatedBuildInputs.

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

I'm inexperienced at all this stuff, sorry if I got anything wrong.

Notify maintainers

cc @