Revert to a commit by a SHA hash in Git?

If you want to commit on top of the current HEAD with the exact state at a different commit, undoing all the intermediate commits, then you can use reset to create the correct state of the index to make the commit.

# Reset the index and working tree to the desired tree
# Ensure you have no uncommitted changes that you want to keep
git reset --hard 56e05fced

# Move the branch pointer back to the previous HEAD
git reset --soft HEAD@{1}

git commit -m "Revert to 56e05fced"

What git-revert does is create a commit which undoes changes made in a given commit, creating a commit which is reverse (well, reciprocal) of a given commit. Therefore

git revert <SHA-1>

should and does work.

If you want to rewind back to a specified commit, and you can do this because this part of history was not yet published, you need to use git-reset, not git-revert:

git reset --hard <SHA-1>

(Note that --hard would make you lose any non-committed changes in the working directory).

Additional Notes

By the way, perhaps it is not obvious, but everywhere where documentation says <commit> or <commit-ish> (or <object>), you can put an SHA-1 identifier (full or shortened) of commit.

It reverts the said commit, that is, adds the commit opposite to it. If you want to checkout an earlier revision, you do:

git checkout 56e05fced214c44a37759efa2dfc25a65d8ae98d