_env kept an inherited WORKSPACE_ROOT, so every helper that sources the
wrapper (lib.sh's _init_herdr_isolation) rewrote <that workspace>/.mam/shim/
herdr - another workspace's during the PR #51 review (v4.8.7 review, claude).
Only dropping it is not enough: lib.sh then derives the checkout itself, and
conftest keeps a WORKSPACE_ROOT that names this checkout, so the run would
rewrite the checkout's own shim (the real one when this is the main
checkout). _env now sets WORKSPACE_ROOT to the test's tmp dir.
Test: with a sentinel WORKSPACE_ROOT in the environment, _run_both and a
direct _env run leave the sentinel empty and the checkout's shim untouched,
and the shell sees the tmp dir. With the old _env the sentinel gets
.mam/shim/herdr.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HCGpJXhSZasJLU38ksDghe