Ah hah! That's the problem. It's not in the local version.
Next question, how do I get the local version to include it?
Looking at `compile-internal', it seems you'll have to do
things differently.
The simplest is:
(require 'compile)
(add-to-list 'compilation-error-regexp-alist
'("\\[javac\\] *\\(/[^:]+\\):\\([^:]*\\):" 1 2))
and if you don't want to have to preload compile.el from your .emacs file
(I personally hate it when I have to do that), you'l have to use something
like eval-after-load (a bit untidy) or to setq error-regexp-alist (really
ugly and likely to break in a future version of compile.el).