new_contents: from spack import *
  
  class Julia(Package):
      """The Julia Language: A fresh approach to technical computing"""
      homepage = "http://julialang.org"
      url      = "http://github.com/JuliaLang/julia/releases/download/v0.4.2/julia-0.4.2.tar.gz"
  
      version('0.4.2', 'ccfeb4f4090c8b31083f5e1ccb03eb06')
  
      # Build-time dependencies
      # depends_on("cmake")
      # depends_on("awk")
      # depends_on("m4")
      # depends_on("pkg-config")
  
      # Run-time dependencies
      #TODO depends_on("arpack")
      #TODO depends_on("fftw")
      #TODO depends_on("git")
      #TODO depends_on("gmp")
      # depends_on("libedit")
      #TODO depends_on("mpfr")
      #TODO depends_on("pcre2")
      # depends_on("zlib")
  
      # BLAS and LAPACK: Julia prefers 64-bit versions on 64-bit systems. OpenBLAS
      # has an option for this; make it available as variant.
  
      # LLVM: Julia works only with specific versions, and might require patches.
      # Thus we let Julia install its own LLVM.
  
      # Other possible dependencies:
      # USE_SYSTEM_OPENLIBM=0
      # USE_SYSTEM_OPENSPECFUN=0
      # USE_SYSTEM_DSFMT=0
      # USE_SYSTEM_SUITESPARSE=0
      # USE_SYSTEM_UTF8PROC=0
      # USE_SYSTEM_LIBGIT2=0
  
      def install(self, spec, prefix):
          options = ["CC=cc",
                     "CXX=c++",
                     "FC=fc",
                     #TODO "USE_SYSTEM_ARPACK=1",
                     #TODO "USE_SYSTEM_FFTW=1",
                     #TODO "USE_SYSTEM_GMP=1",
                     #TODO "USE_SYSTEM_MPFR=1",
                     #TODO "USE_SYSTEM_PCRE=1",
                     "prefix=%s" % prefix]
          with open('Make.user', 'w') as f:
              f.write('\n'.join(options) + '\n')
          which('env')()
          which('env')('which', 'cc')
          make()
          make("install")
  
subject: Build Julia