In tcl-8.4.15-1.fc8, libtcl8.4.so contains no SONAME record. Run objdump -p /usr/lib/libtcl8.4.so | grep SONAME to verify this. This implies that incorrect library name will be recorded in the NEEDED fiels of executables linked against this library. The library is typically found through the symlink /usr/lib/libtcl.so, thus the resulting binary has "NEEDED libtcl.so". This info is picked by find-provides, so one of the symptoms is a broken require in the resulting rpm. See http://www.redhat.com/archives/fedora-devel-list/2007-August/msg00471.html for an example.