X_TEST_PACE_INVALID
Means
ULTIMATE_TEST_PACE is not a number at or above 1
Typical cause
the variable the gate sets on each test run it starts was set by hand to a value that does not parse, or to one below 1
Fix
env -u ULTIMATE_TEST_PACE bun test <file> — the gate measures the pace and sets it itself; unset is pace 1