Re: git svn rebase - could not detach HEAD

[Junio C Hamano <gitster@pobox.com>]

"Tony Stubbs" <antony.stubbs@gmail.com> writes:

> $ git svn rebase
> First, rewinding head to replay your work on top of it...
> could not detach HEAD
> rebase refs/remotes/git-svn: command returned error: 1

It is somewhat unfortunate that git-svn does not say anything about what
ref it is trying to rebase onto here.  I do not use git-svn nor know much
about the code myself, but here are some ideas.

 * Try "rebase --dry-run" and see what you see from this part of the code:

        sub cmd_rebase {
                ...
                if ($_dry_run) {
                        print "Remote Branch: " . $gs->refname . "\n";
                        print "SVN URL: " . $url . "\n";
                        return;
                }

   Most interesting is what $gs->refname is;

 * If you are using recent enough git (I think 1.5.2 is Ok), update your
   copy of git-rebase like this, so that you would at least see *why* you
   cannot detach HEAD.  It is possible that git-svn is giving a nonsense
   ref to detach to.

diff --git a/git-rebase.sh b/git-rebase.sh
index e2d85ee..7825f88 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -376,9 +376,7 @@ fi
 
 # Detach HEAD and reset the tree
 echo "First, rewinding head to replay your work on top of it..."
-git checkout "$onto^0" >/dev/null 2>&1 ||
-	die "could not detach HEAD"
-# git reset --hard "$onto^0"
+git checkout -q "$onto^0" || die "could not detach HEAD"
 
 # If the $onto is a proper descendant of the tip of the branch, then
 # we just fast forwarded.