The swiftly toolchain used by the vminit-image CI resolves Foundation/ Virtualization but not the 'os' overlay, so 'import os' failed with "no such module 'os'". Guarding the diagnostic logger degrades it to a no-op under such toolchains while local (Xcode) builds keep it. Co-Authored-By: Claude Opus 4.8 <[email protected]>