Simulating an empty git repository without having said repository on disk

Hi all,

for vcsh[1], I need a rather hackish feature: List all files untracked by vcsh. The plan to achieve this is:

Get lists of all files by all repos which' GIT_WORK_TREE is in one directory ($HOME, by default), merge all lists into one and use that as a .gitignore or exclude. Then run `git status` with $GIT_WORK_TREE pointing to $HOME while using said ignore/exclude. That will give me a list of all files & directories which are not tracked by any of the git repos managed by vcsh.

I could create an empty git repo to run this operation in, but that seems wasteful. Thus, I would prefer to run this command against a non-existing, empty git repo. Problem is, I could not find a way to do this.

I know the empty tree's SHA is hard-coded into git so I was hoping there would be a way to trick git using this, but I couldn't find a way.

Any and all help appreciated, even if it's just a "no, this is not possible"

Thanks, Richard

[1] https://github.com/RichiH/vcsh