Pulled my hair out over one today (and a week ago when I first saw the issue)

Setting up development environment. Created test user and test database and used mysqldump to copy data over.

MySQL was executing a function as the wrong user. Checked my config files, checked my config reader, checked my database connection, checked checked checked. Checked everything twice, I felt like Santa.

Changed the password in the config file to make sure it was logging in right. It threw an error still but not one I had expected so I figured the login still worked (My bias was that I thought the config file was not working or the mysql library was caching authentication. Both were wrong but this blinded my debugging. Foolish, I have forgotten my training)

Logged into the database directly via client. *didn't bother executing the function because I was only testing auth*

Think
Think
Think

Search entire project for database username. It's gotta be hard coded by accident SOMEWHERE.

It's not.

Why
Why
Why

Wait.

-- Flashback to how the test db was created -- What's actually in this damn script?

DEFINER `production_user` CREATE PROCEDURE `old_db`.`procedure_name`

Two issues: definer is old user (this is the error I was seeing) and its creating the procedure on the old db (this would be the next error I would have found if I kept going)

Fuck mysqldump. Install mysqldbcopy. Works

Put hair back in head.