git clone specific tag about git2go HOT 4 CLOSED

The thing here is that the option is called "--branch" so that's what we implemented, checking out a particular branch. But as it happens, what git means here is more like "meh, I'll take whatever", which is a behaviour which we haven't implemented.

Until we do accept any string to DWIM, you'd have to perform the switch to the commit in that tag via CheckoutTree() and SetHeadDetached().

from git2go.

Thanks for the hints! I've eventually done something like below:

ref, err := iter.Next()
    for err == nil {
        if ref.IsTag() {
            tagName := strings.TrimPrefix(ref.Name(), "refs/tags/")
            if tagName == "my_tag" {
                fmt.Println("Found the tag", "my_tag")
                obj, err := ref.Peel(git.ObjectTag)
                if err != nil {
                    return fmt.Errorf("Unable to peel the ref: %s\n", err)
                }

                if err := repo.SetHeadDetached(obj.Id(), nil, ""); err != nil {
                    return fmt.Errorf("Checking out tag %s failed: %s", tag, err)
                }

                return nil
            }
        }

        ref, err = iter.Next()
    }

However, I don't understand why I can't Peel the tag reference ? Every time I call ref.Peel(git.ObjectTag) I get the following error:

The git_object of id 'abe8b968b0607f92ddeac31b062208b7ee5fd475' can not be successfully peeled into a tag (git_otype=4).

I had the look at the actual tag hash and it's the same as reported by the error above:

$ cat repo/.git/refs/tags/my_tag
abe8b968b0607f92ddeac31b062208b7ee5fd475

So the tag actually exists. Am I missing something important here ?

Thanks!

from git2go.

The tag reference exists, that doesn't mean there's a tag object underneath. If you look at that ref with git show or git cat-file -t, it should show that there is no tag object there.

But you're not interested in a tag object being there to perform be branch switch. What you need is a commit, so that's what you should be looking for.

You also might be interested in Repository.DwimReference() which will perform this shortname-to-reference conversion that you're doing manually in this code.

from git2go.

Thanks @carlosmn Eventually I went with something like this:

    ref, err := repo.DwimReference(tag)
    if err != nil {
        return fmt.Errorf("Could not find the %s ref: %s\n", ref.Name(), err)
    }

    if err := repo.SetHeadDetached(ref.Target(), nil, ""); err != nil {
        return fmt.Errorf("Checking out tag %s failed: %s", tag, err)
    }

I'm not sure if that's the best way to approach this, but it does seem to do the trick 👍

from git2go.