> I realized that since very recently pkgsrc seems to have a general 
> dependency on coreutils. What did introduce that?

What platform? (IRIX?)

See mk/tools/replace.mk:

# These tools are all supplied by the sysutuils/coreutils package if
# there is no native tool available.
#
_TOOLS.coreutils=       basename cat chgrp chmod chown cp cut date      \
                        dirname echo env expr false head hostname id    \
                        install ln ls mkdir mv nice printf pwd rm rmdir \
                        sleep sort tail tee test touch tr true tsort wc

Maybe that is why?