The cp932 crash in the build gate that only happened on Windows — static detection, behavioral testing, and a negative check

The symptom During the Windows build for v1.6.11, the build gate reported "version number consistency check failed." But the version numbers were correct everywhere. The real cause was not a version mismatch. The build gate in build_app.py calls tools/bump_version.py via subprocess and checks its exit code. The success messages in bump_version.py contained emoji (✅ and similar). On Japanese Windows, the default code page is cp932, which cannot encode those characters. Python raised a UnicodeEncodeError on the very first write to stdout, the process exited non-zero, and the build gate misread that as a version inconsistency. UnicodeEncodeError: 'cp932' codec can't encode character '✅' in position 0 Why it didn't show up on Mac macOS terminals use UTF-8 by default. Running bump_version.py directly or via subprocess on Mac produces no encoding errors — emoji flows through cleanly. On Japanese Windows, the process inherits the cp932 code page. U+2705