anchor.diff:      mpfr m4 binutils emacs gmp
       libX11 xorgproto libXi
       libXext libXt libXaw libXmu
  -    zlib which texinfo readline strace
  +    zlib which texinfo readline
     ];
   
     configureFlags = [
  
positive.code: assert stdenv.cc ? libc ;
  assert stdenv.cc.libc != null ;
  
  stdenv.mkDerivation {
    pname = "gcl";
    version = "2.6.13pre50";
  
    src = fetchgit {
      sha256 = "0vpxb6z5g9fjavrgx8gz8fsjvskfz64f63qibh5s00fvvndlwi88";
      url = "https://git.savannah.gnu.org/r/gcl.git";
      rev = "refs/tags/Version_2_6_13pre50";
    };
  
    postPatch = ''
      sed -e 's/<= obj-date/<= (if (= 0 obj-date) 1 obj-date)/' -i lsp/make.lisp
    ''
    # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=902475
    + ''
      substituteInPlace h/elf64_i386_reloc.h \
        --replace 'case R_X86_64_PC32:' 'case R_X86_64_PC32: case R_X86_64_PLT32:'
    '';
  
    sourceRoot = "gcl/gcl";
  
    patches = [];
  
  
negative.code: { lib, stdenv, fetchgit, mpfr, m4, binutils, emacs, zlib, which
  , texinfo, libX11, xorgproto, libXi, gmp, readline
  , libXext, libXt, libXaw, libXmu } :
  
  assert stdenv ? cc ;
  