Deploying webapps that contain commons-attributes-api.jar or commons-attributes-compiler.jar (downloaded from the Maven repository) fail with a message from ExtensionValidator along the lines of 'Required extension "ant" not found'. This happens because the MANIFEST.MF file in these jars contain wrapped lines. Per the JAR spec, lines longer than 72 bytes have to wrap. These MANIFEST.MF files contain lines like: ant-Implementation-URL: http://www.ibiblio.org/maven/ant/jars/ant-1.5. jar which evidently cause ExtensionValidator to complain. If you edit the MANIFEST.MF files to eliminate the continuation line: ant-Implementation-URL: http://www.ibiblio.org/maven/ant/jars/ant-1.5.jar there are no errors.
There is a bug but not the one describe above. There are also inconsistencies in extension names between the jars that mean, even with the bug fixed, these deps will never be satisfied. The bug has been fixed in trunk here: http://svn.apache.org/viewvc?rev=691282&view=rev This patch has been proposed for 5.5.x and 6.0.x
This has been fixed in 6.0.x and will be in 6.0.19 onwards.
This has been fixed for 5.5.x and will be included in 5.5.28 onwards.