In addion to my previous message.

Oleg Pykhalov <go.wigust@gmail.com> writes:

> The following patch allows to use 'vc-chlog' in the Git worktree instead
> of getting “can't determine version control system for DIRECTORY”.

Probably a directory is needed, too.  I was little bit confused about
that directory is a file and it worked for the first time because I have
another version of vc-dwim installed simultaneously.  Apologies.

Here is a new patch.