Outputting to log in Rails startup

I’d like to output a couple messages to the log in the startup process
– like in environment.rb, or an initializer, or a
config.after_initialize block, or what have you.

But I can’t get any of those to work, can’t figure out a way to put
anything anywhere in the app startup process that results in something
written to the log.

The reason I’d like to do this is to check certain application state and
just output at startup, so it’s there in the log. For instance, what
plugins or gems are loaded (since there’s lots of code that silently
degrades to use certain gem if it’s there, another gem if it’s not. Like
Nokogiri vs. REXML and such.) So I guess i need it to be at a point in
the startup process after my config.gems have been loaded too – but
even aside from that, i can’t get any log output at all to show up.

Am I missing something? Any hints?