It's missing the journal module upon execution.

Traceback (most recent call last):
  File "/nix/store/wp06mrdzjbmiyxvz5m2rrsmf6h8zapv4-rednotebook-2.11.1/bin/.rednotebook-wrapped", line 7, in <module>
    import journal
ModuleNotFoundError: No module named 'journal'

The import journal error is expected as it comes from this:

try:
    # Load module from same directory
    import journal
    print('Starting RedNotebook from the source directory')
    journal.main()
except ImportError:
    # Load installed module
    import rednotebook.journal
    rednotebook.journal.main()

The actual error (also present in the current version 2.8) is:

Traceback (most recent call last):
  File "rednotebook-2.8/bin/.rednotebook-wrapped", line 12, in <module>
    import rednotebook.journal
  File "rednotebook-2.8/lib/python3.7/site-packages/rednotebook/journal.py", line 43, in <module>
    gi.require_version("Gtk", "3.0")
  File "python3.7-pygobject-3.32.1/lib/python3.7/site-packages/gi/__init__.py", line 129, in require_version
    raise ValueError('Namespace %s not available' % namespace)
ValueError: Namespace Gtk not available

It happens because Gtk was not added to GI_TYPELIB_PATH. gobject-introspection did not add it because it only looks at the packages at the hostOffset. (It had looked at gtk3 before, but cross-compilation support must have been improved.) I have fixed this by moving gobject-introspection from nativeBuildInputs to buildInputs in the additional commit to this PR: 066c08b .

@jtojnar, my fix will break if make_gobject_introspection_find_gir_files is moved to $targetOffset (#56943 (comment)). Should I list gobject-introspection in both nativeBuildInputs and buildInputs, or just disable strictDeps?

I have decided to disable strictDeps until gobject-introspection in nativeBuildInputs is supported .