This is 10.13.2 with XCode 9.2 $ mkdep *.c mkdep: error: unable to find utility "mkdep", not a developer tool or in PATH $ which mkdep /usr/bin/mkdep $ echo $PATH /Users/hans/bin:/opt/local/bin:/opt/local/sbin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin Am I missing something obvious? Jan