The problem I have come up against now is that the MySQL server is running on a socket in a location other than the default MySQL socket, so the DBD::mysql package doesn't pass the make test stage.

I assume that by "socket", you mean port number? I think MySQL uses 3306 by default.

Well, when I run perl Makefile.PL, it asks which host the test database to use is on, and one possibility it offers is the host:port syntax. So: just enter your special portnumber here, after the colon, with "localhost" or the empty string in front of the colon.

I did notice that it only does so with a freshly decompressed archive. So delete it all, decompress the archive again, chdir and do `perl Makefile.PL`.