better way to find Git.pm officially?

I'm using Git.pm in a git subcommand. There doesn't (yet :) seem to be an official way to *find* the directory Git.pm was installed in to add it to my @INC, so I can up with this ugly hack:

    #!/usr/bin/perl
    use strict;

    use lib $ENV{GITPERLLIB}
      ? split(/:/, $ENV{GITPERLLIB})
      : do {
        chomp(my $exec_path = qx{git --exec-path});
        open my $gitsvn, "<", "$exec_path/git-svn" or die "Cannot find
      git-svn";
        {
          last unless local $_ = readline $gitsvn;
          redo unless m{\Ause lib.*GITPERLLIB.*\|\| "(.*)"};
          "$1";
        }
      };

    use Git;

As in, find the git-svn binary (via git --exec-path), parse its second line to see where the git installer put the GITPERLLIB, and then add that myself.

Is there a simpler way? Can we get "git --perl-path" added to the binary or something?