The setup script refused to provision, reporting /opt/flutter/bin/cache and
/opt/android-sdk unwritable by the service account, while a touch as that same
account succeeded.
Cause: this machine's /usr/bin/test is uutils coreutils 0.8.0, whose -w does
not credit supplementary group membership. Write access to both directories
comes from the flutterdev group rather than the owner bits, so -w reports false
for any account that should be building here — including the developer's own.
-r and -x pass only because `other` carries r-x, which is what made the failure
look ACL-shaped. bash's builtin [ -w ] evaluates it correctly, but sudo execs
the external binary, so the builtin was never in play.
Replaced with a real write probe: create a file as the service account and
remove it. That tests the operation a build actually performs and is immune to
whichever test implementation is installed, which is the better check
regardless of the bug that prompted it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
mikkeli
ae2033865c