CityGen 0.2.1 (Windows)

CityGen 0.2.1 Release Notes

Released on August 20, 2026.

This is a hot-fix release for the Windows installer build. There are no changes
to application code or generated output — it exists solely to make the packaged
0.2.0 executable start.

The problem

The 0.2.0 Windows build failed immediately on launch with:

_tkinter.TclError: invalid command name "::msgcat::mcmset"

ttkbootstrap initializes localization at startup, which requires Tcl's
msgcat package (version 1.6+, for the ::msgcat::mcmset command). That
package was not bundled, so the interpreter had no such command.

The cause

The PyInstaller Tcl/Tk hook only collected the tcl8.6/ and tk8.6/ script
directories. The Tcl 8.x "module" packages — msgcat, http, tcltest, and
friends — ship as .tm files under a separate tcl8/ directory that sits
beside tcl8.6/, not inside it, so msgcat was never included.

The fix

The hook now also bundles the tcl8/ module tree to the bundle root, where Tcl
looks for it (the module path is resolved relative to the interpreter library,
i.e. [file dirname $tcl_library]/tcl8). package require msgcat now succeeds
and the application starts normally.

Upgrade notes

• No configuration or output changes.
• Rebuild the Windows installer to pick up the fix.

Verification

• python -m pytest
• python packaging/build_windows_release.py --clean
• Launch the built executable and confirm the GUI opens.