rpm --help contains long option entries like:
-e, --erase=<package>+ erase (uninstall) package
-F, --freshen=<packagefile>+ upgrade package(s) if already installed
-U, --upgrade=<packagefile>+ upgrade package(s)
...but the long option syntax does not actually work when invoked like the above, they need to be given like "--erase foo" or "--upgrade foo" instead, i.e. the "=" needs to be replaced by whitespace. For some options the "=" appears to work (for example --rcfile=foo) but not for any of the above.
No idea if this is an upstream rpm or popt issue, so reporting it here.
It's an popt-issue indeed (and old one at that IIRC), supposedly fixed in popt >= 1.14 but there hasn't been a whole lot of activity in updating Fedora's popt to a more recent version... (see bug 448286)
*** This bug has been marked as a duplicate of bug 293531 ***