You might want to do this if you want to install the latest snapshot and no pre-built release is available. OR you might want MacVim to use a custom Python installation instead of the default one on the system path. This latter was my motivation. Once you have downloaded and unpacked the code base that you want to build, step into the `src/` subdirectory:

$ cd src

Before proceeding, make sure that your Python installations have been built with the "``--enable-shared``"! If this is not the case, no matter how you build MacVim, you will not have Python available. Rebuild your Pythons with this flag and reinstall if necessary before proceeding. Then configure the build with:

$ export LDFLAGS=/usr/platform/lib
$ CC=clang ./configure \
    --enable-perlinterp \
    --enable-pythoninterp \
    --enable-python3interp \
    --enable-rubyinterp \
    --enable-cscope \
    --enable-gui=macvim \
    --with-mac-arch=intel \
    --with-features=huge

Then build:

$ make

The "`MacVim.app`" build product will be in the "`MacVim/build/Release`" subdirectory, and can be tested by:

$ open MacVim/build/Release/MacVim.app

Or installed by:

$ cp MacVim/build/Release/MacVim.app /Applications