Up to and including 10.7.4, OS X shipped with 'md' at '/usr/bin/md',
a BSD utility to manage dependencies. Since OS X 10.8, 'md' is
missing, which causes compilation of older software to fail with an
error message along the lines of 'make: md: No such file or directory'.
This formula uses the source for 'md' from OS X 10.7.4.
ClosesHomebrew/homebrew#13612.
Signed-off-by: Misty De Meo <mistydemeo@gmail.com>
