You can now run different PHP versions per project: Release v3.0.0-beta-0.1


This section will contain common problems and how to resolve them. It will grow over time once there are more issues reported.

See also


Update the Devilbox

Issues are constantly being fixed. Before attempting to spend too much time digging into your issue, make sure you are running the latest git changes and have pulled the latest Docker images.

Also keep in mind that configuration files might change, so ensure to diff the default ones against your currently active ones for added, removed or changed values.

Table of Contents

What to always do first

Before going into the issues below, always do the following

1. Ensure stopped container are removed

# Ensure everything is stopped
host> docker-compose stop
host> docker-compose kill
host> docker-compose rm -f

2. Ensure config is normalized

# Ensure .env file is normalized
host> cp env-example .env

3. Statup minimal

# Test everything with the minimal stack
host> docker-compose up php httpd bind

4. Run config checker

# Run the bash script in the Devilbox git directory
host> ./


Sudden unexplained problems on Windows

In case something stopped working for no reason, check out other Docker container. If you experience similar issues as well, check for any unattended Windows updates or updates to Docker itself. If those exist, try to revert them and see if that was the cause.

I heard many bug stories from fellow Windows users so far. A good contact point for that is the Docker forum itself:

A few general things you should always do before attempting to open up issues are:

1. Used default settings from env-example

Try using the exact settings from env-example as variables might have been updated in git.

# Ensure everything is stopped
host> cp env-example .env

2. Clean, updated and minimal start

# Ensure everything is stopped
host> docker-compose stop
host> docker-compose kill
host> docker-compose rm -f

# Ensure everything is updated
host> docker-compose pull

# Start again
host> docker-compose up php httpd bind

3. Reset Docker credentials:

As it might sound strange, this fix might indeed solve a lot of problems on Windows. Go to your Docker settings and reset your credentials.

4. Shared volumes:

Ensure all your Devilbox data (Devilbox directory and project directory) are within the volumes that are shared by Docker. If not add those in the Docker settings.

No Space left on Device

If on Docker for Mac you get an error during docker pull similar to the following one:

write /var/lib/docker/tmp/GetImageBlob220119603: no space left on device

It means the file where MacOS stores the docker images is full. The usual way is to delete unused images and volumes to free up space or increase this volumes size.

However, depending on the version of Docker some of the above suggestions may not work and you have to get support from the docker/for-mac GitHub repository or forum.

Address already in use

One of the Docker container wants to bind to a port on the host system which is already taken. Figure out what service is listening on your host system and shut it down or change the port of the affected service in the Devilbox .env file.

Some examples of common error messages:

Error starting userland proxy: Bind for unexpected error (Failure EADDRINUSE)

Unable to finish Pulling as unauthorized: incorrect username or password

This error might occur if you are already logged into a different Docker repository. To fix this error, sign out of your currently logged in repository and try again.

localhost or not found

If you are using Docker Toolbox, the Devilbox intranet is not available on localhost or, but rather on the IP address of the Docker Toolbox machine.

ERROR: Version in “./docker-compose.yml” is unsupported

This simply means your Docker and/or Docker Compose versions are outdated.

See also



Performance issues on Docker for Mac

By default Docker for Mac has performance issues on mounted directories with a lot of files inside. To overcome this issue you can apply different kinds of caching options to the mount points.

DNS issues

zone ‘localhost’: already exists previous definition

bind_1 | /etc/bind/devilbox-wildcard_dns.localhost.conf:1:
zone 'localhost': already exists previous definition:

This error occurs when using localhost as the TLD_SUFFIX.

SSL issues

unable to get local issuer certificate

Errors occurred when trying to connect to
cURL error 77: error setting certificate verify locations: CAfile: certificate ./ca/cacert.pem CApath: /etc/ssl/certs

This issue might arise if you set TLD_SUFFIX to an official top level domain such as .com. What happens is that the bundled DNS server does a catch-all on the TLD and redirects all name resolution to the Devilbox’s PHP container IP address.

If you want to access in that case, the request goes to the PHP container which does not have a valid SSL certificate for that domain.

Do not user official TLD’s for TLD_SUFFIX.

Web server issues

Warning: DocumentRoot [/var/www/default/htdocs/] does not exist

This error is most likely to only occur on Docker for Windows and is just a result of not working volumes mounts.

403 forbidden

This error might occur for the Devilbox intranet or custom created projects.

File and directory permissions

On of the cause could be wrongly set file and directory permissions.

First ensure the cloned git directory is readable for users, groups and others.

For the Devilbox intranet, ensure the .devilbox/ directory is readable for users, groups and others. Also check files and directories within.

For projects, ensure an index.php or index.html exists and that all files and directories are readable for users, groups and others.

Shared volumes

This might additionally occur on MacOS or Windows due to the Devilbox and/or its projects not being in the standard location of Docker Shared volumes.

Check your Docker settings to allow shared volumes for the path of the Devilbox and its projects.

504 Gateway timeout

This error occurs when the upstream PHP-FPM server takes longer to execute a script, than the timeout value set in the web server for PHP-FPM to answer.

For that to fix one must increase the PHP-FPM/Proxy timeout settings in the .env file. HTTPD_BACKEND_TIMEOUT

PHP issues

Fatal error: Cannot redeclare go()

If you encounter this error, it is most likely that your current project declares the PHP function go() and that you have enabled the swoole module which also provides an implementation of that function.

To mitigate that issue, make sure that the swoole module is disabled in .env.

Database issues

Cannot connect to MySQL after restart

This error usually occurs when you import a MySQL dump including the mysql database itself, which will overwrite the user permissions and thus you won’t be able to connect anymore with the settings specified in .env.

Invalid bind mount spec

This error might occure after changing the path of MySQL, PgSQL, Mongo or any other data directory.

When you change any paths inside .env that affect Docker mountpoints, the container need to be removed and re-created during the next startup. Removing the container is sufficient as they will always be created during run if they don’t exist.

In order to remove the container do the following:

host> cd path/to/devilbox
host> docker-compose stop

# Remove the stopped container (IMPORTANT!)
# After the removal it will be re-created during next run
host> docker-compose rm -f

[Warning] World-writable config file ‘/etc/mysql/docker-default.d/my.cnf’ is ignored

This warning might occur when using Docker Toolbox and the Devilbox on Windows and trying to apply custom MySQL configuration files. This will also result in the configuration file not being source by the MySQL server.

To fix this issue, you will have to change the file permission of your custom configuration files to read-only by applying the following chmod command.

# Nagivate to devilbox git directory
host> cd path/to/devilbox

# Navigate to the MySQL config directory (e.g.: MySQL 5.5)
host> cd cfg/mysql-5.5

# Make cnf files read only
host> chmod 0444 *.cnf

[MariaDB] Assertion failure when executing prepared statement with ? in IN list

Some MariaDB versions are affected by MDEV-27937 bug, use a fixed version or set in_predicate_conversion_threshold variable to a higher value.

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