mariadb reads and get confused by /etc/mysql/ config files

[jefft]

What happened?

Mariadb 11.4 (mariadb@latest) always seems to read /etc/mysql/mariadb.cnf, unless --no-defaults is specified. This causes mariadbd to fail to start if one has another version of MariaDB installed via system packages, with more extensive plugins. E.g. with debian mariadb-server-10.5 installed:

$ devbox run mariadbd --verbose 
Info: Running script "mariadbd" on /tmp/mariadbtest
2026-07-06 18:52:55 0 [Note] Starting MariaDB 11.0.4-MariaDB-log source revision 48af85db217a88409e6aac51bf86e3bf525d8f07 as process 938257
2026-07-06 18:52:55 0 [ERROR] mariadbd: Can't open shared library '/nix/store/23nb6k2y7cp4g46gbhpkq6pcc8l61y35-nix-shell-env/lib/mysql/plugin/provider_bzip2.so' (errno: 20, cannot open shared object file: Not a directory)
2026-07-06 18:52:55 0 [ERROR] Couldn't load plugins from 'provider_bzip2.so'.
2026-07-06 18:52:55 0 [ERROR] mariadbd: Can't open shared library '/nix/store/23nb6k2y7cp4g46gbhpkq6pcc8l61y35-nix-shell-env/lib/mysql/plugin/provider_lz4.so' (errno: 20, cannot open shared object file: Not a directory)
2026-07-06 18:52:55 0 [ERROR] Couldn't load plugins from 'provider_lz4.so'.
2026-07-06 18:52:55 0 [ERROR] mariadbd: Can't open shared library '/nix/store/23nb6k2y7cp4g46gbhpkq6pcc8l61y35-nix-shell-env/lib/mysql/plugin/provider_lzma.so' (errno: 20, cannot open shared object file: Not a directory)
2026-07-06 18:52:55 0 [ERROR] Couldn't load plugins from 'provider_lzma.so'.
2026-07-06 18:52:55 0 [ERROR] mariadbd: Can't open shared library '/nix/store/23nb6k2y7cp4g46gbhpkq6pcc8l61y35-nix-shell-env/lib/mysql/plugin/provider_lzo.so' (errno: 20, cannot open shared object file: Not a directory)
2026-07-06 18:52:55 0 [ERROR] Couldn't load plugins from 'provider_lzo.so'.
2026-07-06 18:52:55 0 [ERROR] mariadbd: Can't open shared library '/nix/store/23nb6k2y7cp4g46gbhpkq6pcc8l61y35-nix-shell-env/lib/mysql/plugin/provider_snappy.so' (errno: 20, cannot open shared object file: Not a directory)

The the goal of Devbox is "portable, isolated dev environments" then I suggest the devbox mariadbd wrapper should specify --no-defaults, so that stuff in /etc cannot interfere.

Steps to reproduce

mariadbd replication

# First let's create a setting in /etc that will trip up mariadbd:
echo -e "[server]\nunknown_param_to_break_mariadbd_devbox_testing=true" | sudo tee -a /etc/mysql/mariadb.cnf

# Create a devbox loaded with mariadb
mkdir /tmp/mariadbtest
cd /tmp/mariadbtest
devbox init
devbox add mariadb

devbox run mariadbd --verbose

On my PC, this command prints:

jturner@jturner-desktop:/tmp/mariadbtest$ devbox run mariadbd --verbose
Info: Running script "mariadbd" on /tmp/mariadbtest
Info: Ensuring packages are installed.
✓ Computed the Devbox environment.
Installing MariaDB/MySQL system tables in '/tmp/mariadbtest/.devbox/virtenv/mariadb/data' ...
2026-07-06 19:32:28 0 [ERROR] /tmp/mariadbtest/.devbox/nix/profile/default/bin/mariadbd: unknown variable 'unknown_param_to_break_mariadbd_devbox_testing=true'
2026-07-06 19:32:28 0 [ERROR] Aborting

Installation of system tables failed!  Examine the logs in
/tmp/mariadbtest/.devbox/virtenv/mariadb/data for more information.

The problem could be conflicting information in an external
my.cnf files. You can ignore these by doing:

    shell> /nix/store/91qvw7g5q01wrwmg10k6fp32336ymsk2-mariadb-wrapped/bin/.mysql_install_db-wrapped --defaults-file=~/.my.cnf

You can also try to start the mariadbd daemon with:

    shell> /tmp/mariadbtest/.devbox/nix/profile/default/bin/mariadbd --skip-grant-tables --general-log &

and use the command line tool /tmp/mariadbtest/.devbox/nix/profile/default/bin/mariadb
to connect to the mysql database and look at the grant tables:

    shell> /tmp/mariadbtest/.devbox/nix/profile/default/bin/mariadb -u root mysql
    MariaDB> show tables;

Try '/tmp/mariadbtest/.devbox/nix/profile/default/bin/mariadbd --help' if you have problems with paths.  Using
--general-log gives you a log in /tmp/mariadbtest/.devbox/virtenv/mariadb/data that may be helpful.

The latest information about mariadb-install-db is available at
https://mariadb.com/kb/en/installing-system-tables-mysql_install_db
You can find the latest source at https://downloads.mariadb.org and
the MariaDB discuss email list at https://lists.mariadb.org/postorius/lists/discuss.lists.mariadb.org/

Please check all of the above before submitting a bug report
at https://mariadb.org/jira

Error: error running script "mariadbd" in Devbox: exit status 7

(remember to remove the lines from /etc/mysql/mariadb.cnf afterwards)

mysqld replication

Surprisingly (to me) mysql@latest is the same thing as mariadb@latest:

mkdir /tmp/mysqltest
cd /tmp/mysqltest
devbox init
devbox add mysql
devbox run mysqld -V
Info: Running script "mysqld" on /tmp/mysqltest
/nix/store/73k5sh1dzmj77k9v6jpfxrjswixzw6s1-mariadb-wrapped/bin/.mysqld-wrapped  Ver 10.6.12-MariaDB-log for Linux on x86_64 (MariaDB Server)

Command

No response

devbox.json

Devbox version

0.17.5

Nix version

nix (Nix) 2.28.3

What system does this bug occur on?

Linux (x86-64)

Debug logs

No response