Hmm, that lead to the following immediately:

bash-3.2$ sudo make vastness
( cd niml/ ; make all 'CC=gcc -O2 -DDARWIN -m64 -Wcomment -Wformat -DUSE_TRACING -DHAVE_XDBE -no-cpp-precomp -UDONT_USE_MCW_MALLOC ' ; /bin/mv -f *.o .. ; )
clang: error: no such file or directory: '( cd niml/ ; make all 'CC=gcc -O2 -DDARWIN -m64 -Wcomment -Wformat -DUSE_TRACING -DHAVE_XDBE -no-cpp-precomp -UDONT_USE_MCW_MALLOC ' ; /bin/mv -f *.o .. ; )'
clang: error: no input files
make: *** [niml_b64.o] Error 1

The /usr/bin/gcc one is the Apple one:

bash-3.2$ /usr/bin/gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 6.0 (clang-600.0.51) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin13.4.0
Thread model: posix


The one from macports is here:

bash-3.2$ /opt/local/bin/gcc-mp-4.8 --version
gcc-mp-4.8 (MacPorts gcc48 4.8.3_0) 4.8.3
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

And I tried using that explicitly in the makefile with 'SHELL=/opt/local/bin/gcc-mp-4.8', but that gave an immediate error as well:

bash-3.2$ sudo make vastness
( cd niml/ ; make all 'CC=gcc -O2 -DDARWIN -m64 -Wcomment -Wformat -DUSE_TRACING -DHAVE_XDBE -no-cpp-precomp -UDONT_USE_MCW_MALLOC ' ; /bin/mv -f *.o .. ; )
gcc-mp-4.8: error: ( cd niml/ ; make all 'CC=gcc -O2 -DDARWIN -m64 -Wcomment -Wformat -DUSE_TRACING -DHAVE_XDBE -no-cpp-precomp -UDONT_USE_MCW_MALLOC ' ; /bin/mv -f *.o .. ; ): No such file or directory
gcc-mp-4.8: fatal error: no input files
compilation terminated.
make: *** [niml_b64.o] Error 1