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.
for an example.