[Feature Request] Support for VCS as project's build-depends

[winterland1989]

I'm aware of #3226 , actually this issue followed this discussion, simply put, i want to be able express my build-depends like this:

  build-depends:        base >=4.8 && <4.9
                    ,   [email protected]  bc4c354 /subfolder

The VCS line format can be vcs-uri [optional commit-hash] [optional subfolder], or anyother things that support these instructions. Is this feature under working now?

[23Skidoo]

Seems to be a duplicate of #2189. I don't think anyone is working on this currently.