Why does vscode create a index.lock sometimes when switching branches? Specifically, if the previous branch I just had open had some thing in package-lock.json and I just wanted it reset did a git reset --hard? FYI, I am using node 8. Here is a screenshot:
Git creates index.lock whenever it is updating the index. (In fact, the index.lock lock file itself is the new index being built, to be swapped into place once it's finished. But this is an implementation detail.) Git removes the file automatically (in fact, by swapping it into place) once it has finished the update. At that point, other Git commands are free to lock and then update the index, though of course, one at a time.
If a Git command crashes, it may leave the lock file in place (which, since it's also the new index, may be incomplete and hence not actually useful). In this particular case, there's no ongoing Git command to complete and hence unlock and allow the next Git command to run.
If the file is there at one point, but not there the next time you try something, that means some Git command was still running (and updating) and you were just too impatient. :-) If you mix different Git commands (and/or interfaces such as GUIs) you may have to manually coordinate to avoid these run-time collisions. Any one interface should coordinate with itself internally.
