How can I get rid of "Lost heads"?

Question

In my first attempt to do something with git I used GitHub for Windows. As it is simple and quite primitive tool I decided to try SmartGit. As I was looking around I discovered I have leftovers over my tests - something called "lost heads". How can I get rid of this garbage? It seemed that

git gc --prune=now

or something similar should work, but nothing changed. I tried googling, but everybody was trying to do reverse thing - restore lost commits from lost head or something similar.

Answer 1

According to the man page, git gc will not garbage collect files which are referenced through the 'reflogs' (.git/logs/<ref-name> files in your repository). These HEADs are exactly what SmartGit/Hg displays and when you remove these logs, the unreferenced commits should be collected by a git gc --prune=now.

Warning Unless there is no really good reason to completely get rid of these commits (like removing sensitive data), you shouldn't do that -- maybe some time later your might be interested in exactly one of these commits. At least, reclaiming disk space is no good reason, in my opinion.

Answer 2

this will remove more than just git gc --prune=now:

git -c gc.reflogExpire=0 -c gc.reflogExpireUnreachable=0 -c gc.rerereresolved=0 \
-c gc.rerereunresolved=0 -c gc.pruneExpire=now gc "$@"

source: https://stackoverflow.com/a/14728706/1069083