The problem isn't that Jasperforge mistakenly contains Apache Commons artifacts, as Teodor suspected. The problem is this: Maven asks Jasperforge for http://jasperforge.org/maven2/commons-lang/commons-lang/2.5/commons-lang-2.5.pom Jasperforge responds with "302 Found", redirecting you to /404.php Maven assumes that the file must have been moved to http://jasperforge.org/404.php so it downloads /404.php Jasperforge replies with 404.php, but it gives it a "200 OK" status code. Maven interprets the 200 status code to mean it worked. So it tries to read it as a pom file but fails because it is actually HTML.I use Nexus to proxy all of my Maven repositories, and I order it so that Maven central is checked before Jasperforge. This eliminates the commons-lang problem I describe, but it doesn't actually fix my problem. That is because if any of my Maven builds requests an artifact that doesn't exist, here is what happens: My maven build asks my Nexus server for .../bogus/bogus/1.0/bogus-1.0.pom Nexus doesn't have that artifact, so it asks Maven central for http://repo1.maven.org/maven2/bogus/bogus/1.0/bogus-1.0.pom Maven central responds with the "404 Not Found" status code. Nexus understands that Maven central doesn't have the requested artifact, so next it checks Jasperforge for http://jasperforge.org/maven2/bogus/bogus/1.0/bogus-1.0.pom Jasperforge responds with the "302 Found", redirecting to /404.php, which responds with "200 OK" Nexus thinks it found the bogus pom file because Jasperforge responded with "200 OK", so it responds back to my maven build with the content of 404.php Maven tries to load that file, but can't because it is actually HTML, not a pom fileEven if I fix my build so it doesn't request bogus artifacts, I can still run into problems when some artifacts use version ranges. In that case, Maven/Nexus will always check both Maven central and Jasperforge for the list of versions available. Jasperforge will respond with HTML instead of the metadata file that contains the list of available version numbers. Again, Nexus/Maven won't be able to parse that file because it is HTML from 404.php. We need Jasperforge to respond with a real 404 status code instead of a 404.php page with a 200 status code when a resource is not found.
