PHP OPcache Serving Stale Code in CI - Clear or Disable for CLI

OPcache stores compiled PHP bytecode for speed. When opcache.validate_timestamps is off (or a process is long-lived), PHP keeps running the cached version of a file even after you change it - so CI executes stale code and a "fixed" test still fails.

What this error means

A code change does not take effect in CI: the old behaviour persists, tests that should pass still fail (or vice versa), and clearing the cache or disabling OPcache makes the new code run. Common with opcache.enable_cli=1 plus disabled timestamp validation.

# opcache.ini
opcache.enable_cli=1
opcache.validate_timestamps=0   # never re-checks files

# CI runs the OLD compiled version of UserService.php even after editing it,
# so the assertion you just fixed still reports the previous result.

Common causes

Timestamp validation disabled

opcache.validate_timestamps=0 is a production optimisation - PHP never re-reads changed files. In CI that means edits within a run are ignored until the cache is cleared.

OPcache enabled for CLI with a shared cache

opcache.enable_cli=1 plus a persisted cache directory across CI steps can serve bytecode compiled from a previous checkout or step.

How to fix it

Enable timestamp validation in CI

Let OPcache re-check files so edits are picked up.

php -d opcache.validate_timestamps=1 -d opcache.revalidate_freq=0 bin/run.php

Disable OPcache for CLI in CI

For correctness over speed, turn off CLI OPcache during tests.

php -d opcache.enable_cli=0 vendor/bin/phpunit

Clear the cache between steps

1. Call opcache_reset() at the start of a long-lived worker.
2. Avoid persisting the OPcache directory across CI steps.
3. Confirm with php -i | grep opcache which settings are active.

How to prevent it

• Keep opcache.validate_timestamps=1 (or OPcache off) in CI; reserve 0 for production.
• Do not persist the OPcache directory between CI steps.
• Reset OPcache at the start of long-lived workers.

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