Special characters in DBs are a no-go
Written by Simone
Remember: don't ever use special characters in your DB's users password!!
I have been troubleshooting a migration from mariadbd to pgsql for several hours, until I tried changing my password, which, weirdly enough, was working to connect roundcube but gave errors with pgloader. Once I successfully migrated using the same password with those special characters, roundcube wouldn't connect with pgsql, so I made another fighting round! Finally changed my pgsql password to some letters and numbers only and BAM!, it worked.
Then I stopped mariadbd and disabled the service; now I have more than 200MB RAM freed¹.
¹ See previous post.