Open Source®™© obnoxiousness
Spamassassin, which suffers from both perl & open-source, has multiple configuration files and directories (at least on Linux – there’s /etc/mail/spamassassin, with a local.cf, and /usr/share/spamassassin, that also has a local.cf. There are also three different perl module directories that spamassassin creates, each containing basically the same collection of modules, but only one of which is actually looked at. This was great fun when I was trying to turn off the third-party whitelist checks, which had been letting spam through because goddamn spamassassin trusts those third-parties as if they were family members) and it took me several days of debugging (--dbpath is another peeve; it’s not a directory oh no, it’s a combined directory and filename prefix. Huh) before I realized that if I wanted to enable bayesean spam checking I had to configure it in /etc/mail/spamassassin/local.cf instead of (or along with) /usr/share/spamassassin/local.cf.
Ugh. I’m sure someday the “let’s just fuck with it and see what happens” design method that is so beloved in the open source world goes away, but, sheesh, until then it’s a pain in the butt having to rediscover the wheel every time I set up a new machine.