When building Richfaces 3.3.x from source, you might run into the following error:
richfaces\framework\test\src\main\java\org\ajax4jsf\tests\EnumSupportExpressionFactoryWrapper.java:[32,7] org.ajax4jsf.tests.EnumSupportExpressionFactoryWrapper is not abstract and does not override abstract method coerceToType(java.lang.Object,java.lang.Class) in javax.el.ExpressionFactory
The solution to solve this error:
The problem is that there are different versions of the "el-api-1.0.jar" on the Internet.
The official JAR, with 24432 bytes and SHA1 checksum df8c6ce0406676e70c5d018e5fb988be1bcf1024, is available at the usual locations:
RichFaces 3.3.X does not compile when this JAR is used. It needs the "el-api-1.0.jar" from the old Maven 1 repo at http://download.java.net/maven/1/javax.el/jars/ (29309 bytes, SHA1 1e72d5b13b698f99058d35751a29f87ef3066e87).
You don't have to clear the whole local repository or circumvent your Maven proxy. It is just enough to delete all files in %HOME_DIR%\.m2\repository\javax\el\el-api\1.0\ and download http://download.java.net/maven/1/javax.el/jars/el-api-1.0.jar into that folder.