So we generally like to tag our releases in git, like v1.0.0 or what have you.
Github Web UI has a “tag/branch switcher” widget, which lets you look at a particular branch or tag in the Web UI.
You can see it has separate tabs for “branches” and “tags”. Let’s say you get confused, and type “v1.0.0” (a tag) while the “branches” tab is selected (under the text box).
It found no auto-complete for “v1.0.0” in “branches” (although there is a tag with that name it would have found if “tags” tab had been selected), and it “helpfully” offers to create a branch with that name.
Now, if you do that, you’re going to have a new branch, created off master, with the same name as a tag. Which is going to be really confusing. And not what you wanted.
Maybe your muscle memory makes your fingers hit “enter” and you wind up there — but at least it is very clearly identified, it says in fairly big and bold text “Create branch: v1.0.0 (from master)”, at least it warned you, although it’d be easy to miss in a hurry from muscle memory thinking you know what you’re doing.
That’s not the really evil UI yet.
Now let’s go to git’s “compare” UI. At https://github.com/someorg/someproject/compare
A fairly common thing I at least want to do is look at the compare between two releases, or from last release to master. But the ‘compare’ UI doesn’t have the tabs, it will only list or auto-complete from branches.
In a hurry, going from muscle memory, you type in “v1.0.0” anyway.
It does say “nothing to show”. But “v1.0.0” shows up in the list anyway. With a pretty obscure icon I’ve never seen before. Do you know what that icon means? It turns out, apparently, it means “Create branch: v1.0.0 (from master)”.
If confused, or in a hurry, or with your muscle memory outpacing your brain, you click on that line — that’s what happens.
Now you’ve got a branch called “v1.0.0”, created off current master, along with a tag “v1.0.0” pointing at a different SHA. Because many UI’s treat branches and tags somewhat interchangeably, this is confusing. If you do a git checkout v1.0.0, are you going to get the branch or the tag?
It turns out if you go to a github compare UI, like `https://github.com/someorg/someproject/compare/v1.0.0..master`, Github is going to compare the new branch you accidentally made, not the existing tag (showing nothing in the diff, if master hasn’t changed yet). There is no no way to get Github to compare the tag. If you didn’t realize exactly what you did, you’re going to be awfully confused about what the heck is going on.
You’re going to need to figure it out, and delete the branch you just made, which it turns out you can do from the command line with the confusing and dangerous command: ` git push origin :refs/heads/v1.0.0`
And that’s how I lost a couple hours to figuring out “what the heck is going on here?”
What should you do if you want github ‘compare’ web UI for a tag rather than a branch? Turns out, as far as I know, you just need to manually enter the the URL https://github.com/org/project/compare/v1.0.0..v1.0.1 or what have you. The actual UI widgets will not get you there. They’ll just get you to a mess.
Am I missing something? That seems like github web UI is not only not providing for what I would think is a pretty common use (comparing tags), but leading you down a path to disaster when you look for it, no?
Bibliographic Wilderness 