Observed on the mongo-php-driver-2.5 mainline version for "Merge v2.1 into v2.5 (#2173)" (revision 8972b37f9a, 2026-10-14):

• Task: test-ocsp-7.0 on test-debian12-php-8.5-libmongoc-next-stable
• Failure: system failure, 'shell.exec' in function 'bootstrap mongo-orchestration' (step 2.2 of 3); no test results (0 of 69 tests ran)

Context: the same failure signature (test-ocsp-* failing in 'bootstrap mongo-orchestration') hit 9 tasks on the mongo-php-driver-2.1 waterfall on 2026-10-08 and was fixed by a drivers-evergreen-tools update. The v2.5 branch may need the same drivers-evergreen-tools update.

Tracked as part of CI reliability investigation PHPLIB-1938.