Calibre expression got broken recently

[AmandaCameron]

Describe the bug
Calibre on unstable is failing to launch, citing an ImportError

To Reproduce
Steps to reproduce the behavior:

1. Try and launch the calibre desktop app, via your DE of choice, or from the terminal with calibre
2. Get a happy little stack trace wherever the output goes.

Expected behavior
Calibre launches and displays my E-Book collection

Additional context
The stack trace output when it fails to launch is this:

Traceback (most recent call last):
  File "/nix/store/jd2a76h89awrp9dnppafcicvw9q2ydv1-calibre-3.45.2/bin/..calibre-wrapped-wrapped", line 21, in <module>
    sys.exit(calibre())
  File "/nix/store/jd2a76h89awrp9dnppafcicvw9q2ydv1-calibre-3.45.2/lib/calibre/calibre/gui_launch.py", line 73, in calibre
    main(args)
  File "/nix/store/jd2a76h89awrp9dnppafcicvw9q2ydv1-calibre-3.45.2/lib/calibre/calibre/gui2/main.py", line 554, in main
    gui_debug=gui_debug)
  File "/nix/store/jd2a76h89awrp9dnppafcicvw9q2ydv1-calibre-3.45.2/lib/calibre/calibre/gui2/main.py", line 389, in run_gui
    from calibre.gui2.ui import Main
  File "/nix/store/jd2a76h89awrp9dnppafcicvw9q2ydv1-calibre-3.45.2/lib/calibre/calibre/gui2/ui.py", line 42, in <module>
    from calibre.gui2.init import LibraryViewMixin, LayoutMixin
  File "/nix/store/jd2a76h89awrp9dnppafcicvw9q2ydv1-calibre-3.45.2/lib/calibre/calibre/gui2/init.py", line 19, in <module>
    from calibre.gui2.book_details import BookDetails
  File "/nix/store/jd2a76h89awrp9dnppafcicvw9q2ydv1-calibre-3.45.2/lib/calibre/calibre/gui2/book_details.py", line 15, in <module>
    from PyQt5.QtWebKitWidgets import QWebView
ImportError: No module named QtWebKitWidgets

Metadata

• system: "x86_64-linux"
• host os: Linux 4.19.60, NixOS, 19.09pre186408.3d84cffe955 (Loris)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.2.2
• channels(amandac): ""
• channels(root): "nixos-19.09pre186408.3d84cffe955, nixos-unstable-19.09pre182971.a1dd419c1ff"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

[FRidh]

related #65150

[averelld]

I think this was closed on accident due to the "..., partially fixes #65313" message.

There is a typo in --prefix that the colon is attached to PYTHONPATH and PATH. Additionally the qtWrapperArgs are not shell-evaluated in wrapQtApp, so that could be fixed by moving the python --prefix to the wrapping in the installPhase directly like so: wrapQtApp $program --prefix PYTHONPATH : $PYTHONPATH
After that the original / other partial problem returns, and I think @FRidh is fixing that in #56354

[FRidh]

Oops, it's indeed not evaluated.

[ToxicFrog]

With --prefix fixed, it builds, but fails to find msgpack at runtime:

@averelld 's suggestion seems to have fixed it, going to run the server for a bit and see if it explodes.

[worldofpeace]

I can't reproduce this on master. Believe it was fixed.