require 'formula' class NoGcrypt < Requirement satisfy(:build_env => false) { !Formula["libgcrypt"].installed? } def message; <<-EOS.undent This software can fail to compile when libgcrypt is installed. You may need to try: brew unlink libgcrypt brew install libmtp brew link libgcrypt EOS end end class Libmtp < Formula homepage 'http://libmtp.sourceforge.net/' url 'https://downloads.sourceforge.net/project/libmtp/libmtp/1.1.6/libmtp-1.1.6.tar.gz' sha1 'f9e55c75399fc5f4deabcdfa58e1b01b2e6e3283' depends_on NoGcrypt depends_on "pkg-config" => :build depends_on "libusb-compat" def install system "./configure", "--disable-dependency-tracking", "--prefix=#{prefix}" system "make install" end end