# Troubleshooting

Sometimes the WordPress install in the bin/install script can fail. This is usually fixed by increasing the sleep time to allow the MySQL server to start accepting connections.

# ...
sleep 10; # Increase this and retry, it may need to go as high as 30.
# ...

ERROR: readlink /var/lib/docker/overlay2: invalid argument

Often this is due to a corrupted image that needs to be rebuilt without any caches.

docker-compose build --no-cache

Or you can amend the install script to include the --no-cache option, e.g.

-    docker-compose build;
+    docker-compose build --no-cache;
     docker-compose up -d;

If you are on a Linux machine, you will need to uncomment the following within the root .env file:

#USER_ID=1000
#GROUP_ID=1000

Note: You will need to stop and rebuild the containers when changing env vars, e.g. docker-compose stop; docker-compose up --build

Composer can often be quite slow if you have lots of classes and it falls back to filesystem lookups.

They have addressed this with a series of autoloader optimisations.

Typically, Level 1 optimisations composer install -o / composer dump-autoload -o are enough, however with WordPress you are likely to get a large number of autoloader misses due to the fact many plugins and things are not installed via composer.

Therefore, we can have more success with the Level 2 optimisations. Using an authoritative classmap should be ok, because everything we want to autoload through composer should be defined in the classmap and we are unlikely to be declaring classes dynamically.

composer install -a

or

composer dump-autoload -a

If we do come across class not found errors though then we may need to look into APCu caching.

Sometimes query monitor can slow down your local env, particularly if you have xdebug enabled. You can de-activate through the admin or on CLI with:

./bin/docker/wp plugin deactivate query-monitor

To re-activate:

./bin/docker/wp plugin activate query-monitor

Sometimes using wp-memcached can cause slowdown locally due to limited memory on a developers machine (or assigned to the container). To stop using memcached, simply remove the object-cache.php file within wp-content

rm -f wp-content/object-cache.php

To re-enable:

cp wp-content/plugins/memcached/object-cache.php wp-content/object-cache.php

If you're still having trouble, sometimes it can be resolved by re-fetching and re-building fresh images:

docker-compose stop; docker-compose build --no-cache --pull