Latest versions of tcsh does not create symlink /bin/csh. The problem is that dosym does not work in pkg_postinst(). It creates /var/tmp/portage/tcsh-6.14-r2/image/bin/csh symlink on /etc/tcsh. But as it is called in pkg_postinst() then actual copy of image directory in live system was already done. Please, move [ ! -e /bin/csh ] && dosym /bin/tcsh /bin/csh in src_install() or use ln there.
And I need to mention that this bug is only in currently stable tcsh-6.14-r2 ebuild.
Hmmm... it was in src_install, but I was told to do it in pkg_postinst because of non-availability of csh when checking for it. src_install can't check outside the image or something. I'm confused now. Will look into it.
I added tcsh-6.14-r3 which solves this bug by adding the symlink. Also csh is now blocked from tcsh. The fun is that csh stable already blocked tcsh, so there should be noone with both installed...
Marking as fixed... Reopen if you object!