Yorick@YORICK-LAPTOP ~/mozilla
$ cd mozilla/js/src

Yorick@YORICK-LAPTOP ~/mozilla/mozilla/js/src
$ make -f Makefile.ref
cat: ../../dist/WINNT6.0_DBG.OBJ/nspr/Version: No such file or directory
make -f Makefile.ref  WINNT6.0_DBG.OBJ/js32.dll WINNT6.0_DBG.OBJ/js.exe
cat: ../../dist/WINNT6.0_DBG.OBJ/nspr/Version: No such file or directory
make[1]: Entering directory `/home/Yorick/mozilla/mozilla/js/src'
cl -FoWINNT6.0_DBG.OBJ/ -c -MD -Od -Zi -FdWINNT6.0_DBG.OBJ/jsapi.pdb -D_X86_=1 -DXP_WIN -DXP_WIN32 -DWIN32 -D_WINDOWS -D_WIN32 -DWINVER=0x500 -D_WIN32_WINNT=0x500 -nologo -W3   -DDEBUG -DDEBUG_ -IWINNT6.0_DBG.OBJ  -Op -DEXPORT_JS_API jsapi.c
make[1]: cl: Command not found
make[1]: *** [WINNT6.0_DBG.OBJ/jsapi.obj] Error 127
make[1]: Leaving directory `/home/Yorick/mozilla/mozilla/js/src'
make: *** [all] Error 2