anchor.diff:    '';
     postInstall = ''
       sed -i -e "s|basedir=\"\"|basedir=\"$out\"|" $out/bin/mysql_install_db
  -    rm -r $out/mysql-test $out/sql-bench $out/data "$out"/lib/*.a
  -    rm $out/share/man/man1/mysql-test-run.pl.1
  +    rm -r $out/data "$out"/lib/*.a
     '';
   
     passthru = {
  
positive.code: let
  self = stdenv.mkDerivation rec {
    name = "mysql-${version}";
    version = "5.5.58";
  
    src = fetchurl {
      url = "mirror://mysql/MySQL-5.5/${name}.tar.gz";
      sha256 = "1f890376ld1qapl038sjh2ialdizys3sj96vfn4mqmb1ybx14scv";
    };
  
    patches = if stdenv.isCygwin then [
  
negative.code:     "-DINSTALL_MYSQLSHAREDIR=share/mysql"
      "-DINSTALL_DOCDIR=share/mysql/docs"
      "-DINSTALL_SHAREDIR=share/mysql"
      "-DINSTALL_MYSQLTESTDIR="
      "-DINSTALL_SQLBENCHDIR="
    ];
  
    NIX_CFLAGS_COMPILE = [ "-fpermissive" ]; # since gcc-7
  