Why didn't find find my file?

I wanted to import the mysql 'classicmodels' sample database into mysql using phpmyadmin on my localhost.

I got the error:

Quote:

Warning in ./libraries/plugin_interface.lib.php#551 count(): Parameter must be an array or an object that implements Countable

I have had a similar error before, due to a missing bracket in the library file.

So I want to find: plugin_interface.lib.php

I tried

Quote:

find / plugin_interface.lib.php

No result.

I tried

Quote:

sudo find / plugin_interface.lib.php

No result.

I checked my last question here about a similar problem, went to /usr/share/phpmyadmin/libraries/ and there is my file:

plugin_interface.lib.php

Why didn't find find it? How should I find a file when I'm not sure where it is?

In the end I imported classicmodels manually in bash, no problem.