anchor.diff:    '';
   
     configurePhase = ''
  -    cd sys/${platform}
  +    pushd sys/${platform}
       ${lib.optionalString (platform == "unix") ''
         sh setup.sh hints/${unixHint}
       ''}
  -    cd ../..
  +    popd
     '';
   
     postInstall = ''
  
positive.code: 
    makeFlags = [ "PREFIX=$(out)" ];
  
    patchPhase = ''
      sed -e '/^ *cd /d' -i sys/unix/nethack.sh
      sed \
        -e 's/^YACC *=.*/YACC = bison -y/' \
  
negative.code:       -e 's,^CC=.*$,CC=cc,' \
        -e 's,^HACKDIR=.*$,HACKDIR=\$(PREFIX)/games/lib/\$(GAME)dir,' \
        -e 's,^SHELLDIR=.*$,SHELLDIR=\$(PREFIX)/games,' \
        -e 's,^CFLAGS=-g,CFLAGS=,' \
        -i sys/unix/hints/macosx10.10
      sed -e '/define CHDIR/d' -i include/config.h
      sed \
  