Git fetch a specific commit by hash

Question

Git allows to fetch from any given remote and reference, for example

git fetch <remote-url> <reference> 

So that those given commits are available without having to add remotes or creating branches.

This however only works for references, like branch names or tags, but not for specific hashes and thus commits that are not referenced directly anywhere.

Is there a way to fetch a specific commit from a remote?

Answer 1

As today I tried:

git fetch origin <commit-hash> 

And it works like a charm! (git version 2.20.1)

Just be sure the <commit-hash> is the full length reference

Answer 2

See "Pull a specific commit from a remote git repository":
With Git 2.5 (July 2015), you will be able to do:

git fetch --depth=1 <a/remote/repo.git> <full-lenght SHA1> git cat-file commit $SHA1 

If the SHA1 is "reachable" from one of the branch tips of the remote repo, then you can fetch it.

Caveats:

• you need a Git 2.5 remote repo server though, which will handle the uploadpack.allowReachableSHA1InWant config (and you need that config to be set to true, in order to allow a single commit fetch).
• And, as illustrated in crgarridos's answer, you need the full SHA1, and you cannot use git rev-parse, since you don't have all the commits, as noted by Jim Hurne in the comments.