package installation question

I selected a file called DRUtils_1.0.tar.gz as a Local Source File in the
Package Installer and got this result:

* Installing *source* package 'DRUtils' ...
** libs
/Library/Frameworks/R.framework/Resources/bin/SHLIB: line 1: make: command
not found
    npackage installation failed
ERROR: compilation failed for package 'DRUtils'

What is it I am missing? Thanks for any suggestions!