According to http://bugs.gentoo.org/show_bug.cgi?id=239422
merging sys-apps/pcmciautils requires yacc (not just bison) installed.

I have bison installed and the
/usr/bin/yacc --> /usr/bin/yacc.bison
link created by the bison ebuild prevents sys-devel/yacc from merging.

Does the following procedure sound safe?

1. quickpkg bison (in case of disaster)
2. rm /usr/bin/yacc
3. emerge yacc
4. emerge pcmciautils
5. emerge --unmerge yacc
6. emerge bison

thanks,
allan