The schema partition's 52 tests assert structural Schema-to-Cobra contracts over
a single goroutine: none of them call t.Parallel or start a goroutine, so the
race detector has no concurrent access to observe there. The process-global lazy
metadata that does need race coverage (schema_source_root's atomic.Value, the
parameter-binding lazy loaders) is exercised by internal/cli's concurrent tests,
which stay instrumented.
The instrumentation was not free here. The partition shares a single sync.Once
Catalog build whose work is allocation-heavy, and -race made it roughly 11x
slower: 26s -> 291s locally, and 357s of the app shard's 780s in CI. Within that
partition TestFinalSchemaToolsHaveExecutableBaseCommands alone accounted for
262s, not because the test is expensive but because it is the first caller to pay
for the shared snapshot; its 1121 subtests together measure 0.00s.
run_partition now takes the instrumentation mode explicitly and fails closed on
an unrecognized value, so a typo cannot silently drop -race from a partition that
is supposed to carry it.
chichuan
4a33e7e893