On Monday, 11 May 2015 at 08:31:19 UTC, Timothee Cour wrote:

git clone git://github.com/D-Programming-Language/dmd.git
cd dmd
make -f posix.mak MODEL=64

/Applications/Xcode.app/Contents/Developer/usr/bin/make -C src -f posix.mak
no cpu specified, assuming X86
dmd idgen.d
g++ -m64: No such file or directory
--- errorlevel 255
make[1]: *** [idgen] Error 255
make: *** [all] Error 2

Do you
1) already have a version of dmd installed (relatively new requirement)
and
2) have a working g++, whether of clang or gcc variety? On my machine g++ is in /usr/bin and is actually clang, although not as a symbolic link, as a slightly differently configured executable. Don't really know what apple's thinking here was.