System legacy binaries/path problem. Went to http://www.sunfreeware.com/ ,
pkgadd'd diffutils-2.8.1 and rcs-5.7, and we're good to go.

$ hg debuginstall
Checking encoding (ISO8859-1)...
Checking extensions...
Checking templates...
Checking patch...
Checking merge helper...
Checking commit editor...
Checking username...
No problems detected

Thank you for the help!