@U0AQ3HP9U sorry, I am not clear on what you are trying to do, so would need more info to replicate. If you are reverting a commit, then you shouldn't need to specify a file, just the commit you want to revert to. If you want to discard changes in a file that are not committed, then you shouldnt need to specify the file either, as you would just navigate to the file name in magit-status and press x. If you can elaborate what you are doing then I may have some suggestions (other than delete all the local branches you dont need).

I’m trying to reset exactly one file file to an earlier commit. I don’t have any uncommitted changes.

From the magit buffer, I do O to get to the *magit-reset-popup*, then f to reset a file

I then have to enter a commit into Checkout from revision:, complete with narrowing options. I can choose e.g. a branch name or HEAD^^ or whatever.

Writing HEAD^^ takes a long time - once I’ve written HEA, the editor hangs for a while, then the same happens for each subsequent symbol.

Hm, it seems I’m getting narrowing options now when I have to specify the file, after specifying the commit I want to reset to. That’s one problem out of the way.

Now I think I’ll try to remove some state to see if my Checkout from revision: stage can become more snappy.

I do get helm narrowing when prompted for the file name. I suggest its either your project or possibly and a bug in the magit package, or there is a fix in spacemacs that is only in develop. I just opened a simple project with a handful of commits, ran magit status, pressed O, selected master branch and was prompted with the typical helm narrowing popup to choose the file. Suggest you try this on a simpler project with fewer branches before changing anything with spacemacs.

Thanks for helping out, I’ll experiment 🙂