NixOS/nixpkgs — pull request #3510 by copumpkin (2014-08-10 00:55:50+00:00)
Title: Build junit rather than downloading binaries

It should be pretty safe. There's a slight difference in the product in that the old one produced junit.jar and hamcrest.jar, whereas this one produces junit-4.11.jar and hamcrest-1.3.jar. The only junit dependency I could find in nixpkgs (junixsocket) didn't seem to mind, though.