This appears to be a valid SRC_URI: SRC_URI="ev6? ( ftp://ftp.compaq.com/pub/products/linuxdevtools/latest/cpml_ev6- 5.2.0-1.alpha.rpm ) !ev6? ( ftp://ftp.compaq.com/pub/products/linuxdevtools/latest/cpml_ev5- 5.2.0-1.alpha.rpm )" setting FEATURES="cvs" will usually fetch and digest all DISTFILES, however with this SRC_URI only one distfile is collected.
It has been fixed in cvs. I guess it'll be in 2.0.50-r2. *** This bug has been marked as a duplicate of 16159 ***