Sorry, I got confused. Just tested it again, and it works just fine on Mac OS X 10.10 Yosemite. It turns out I was having a different problem related to the library files of Dwarf Fortress v0.43.03. After replacing those with better versions it works fine. Thanks for the help!
Now I just need to get Dwarf Therapist and PyLNP to compile.
Edit: Spent all day trying to get it to compile a second time. Looks like my problem this time was leaving "export MACOSX_DEPLOYMENT_TARGET=10.9" out of my build script.
Posting build script here, so I don't lose it.
mkdir ~/Desktop/dfhack_comptile
cd ~/Desktop/dfhack_comptile
git clone --recursive https://github.com/DFHack/dfhack
cd dfhack
git submodule update --init
xcode-select --install
export MACOSX_DEPLOYMENT_TARGET=10.9
brew tap homebrew/versions
brew install git
brew install cmake
brew install gcc45
export CC=/usr/local/bin/gcc-4.5
export CXX=/usr/local/bin/g++-4.5
sudo cpan
part 1a - Place a "df_osx_v0.43.03" at ~/Desktop/dfhack_comptile/df_osx_v0.43.03/ if there isn't one already.
install XML::LibXML
install XML::LibXSLT
quit
export MACOSX_DEPLOYMENT_TARGET=10.9
export CC=/usr/local/bin/gcc-4.5
export CXX=/usr/local/bin/g++-4.5
mkdir build-osx
cd build-osx
export MACOSX_DEPLOYMENT_TARGET=10.9
export CC=/usr/local/bin/gcc-4.5
export CXX=/usr/local/bin/g++-4.5
cmake .. -DCMAKE_BUILD_TYPE:string=Release -DCMAKE_INSTALL_PREFIX=../../df_osx_v0.43.03
make -j 4 install