With the BOM fixed (shell: pwsh), the build got far enough to compile audiopus_sys, which
does a CMake-from-source build of libopus. The runner's host workdir sits deep under
C:\Windows\System32\config\systemprofile\.cache\act\<hash>\hostexecutor\, so target\debug\build\
audiopus_sys-*\out\build\CMakeFiles\CMakeScratch\TryCompile-*\...\.tlog overran Windows' 260-char
MAX_PATH and MSBuild's tracker failed to create its .tlog (DirectoryNotFoundException -> MSB6003,
"CL.exe konnte nicht ausgeführt werden"). Pointing CARGO_TARGET_DIR at C:\t shortens every nested
build path well under the limit (fixes audiopus_sys + SDL3, both CMake-from-source).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
3a3c353a5e