respect shallow/grafted nixpkgs repositories

[xfnw]

if you attempt to nixpkgs-review pr on a shallow copy of nixpkgs, it will try to download the entire ~4gb of git history

[Mic92]

I don't see a way around this. It currently uses git fetch to download the history of both master and the PR and than needs to perform a merge of one into the other

[SuperSandro2000]

it will try to download the entire ~4gb of git history

For me the entire history is just 1.3 GB big.

We could probably modify the fetch commands to only fetch what we really need but it is a pain to work with shallow repositories since certain things done with the history will just fail in some situations and executing multiple fetches for every user is probably slowing down things more.

[xfnw]

For me the entire history is just 1.3 GB big.

huh... do you have some sort of compression enabled? mine seems to be a lot larger

[xfnw@feesh:~]$ du -sh nixpkgs
3.7G    nixpkgs

[xfnw@feesh:~]$ du -sh nixpkgs/.git
3.6G    nixpkgs/.git

[SuperSandro2000]

Try

du -sh .git
git gc --aggressive
git gc
git repack -Ad
git prune
du -sh .git

[lolbinarycat]

@SuperSandro2000

We could probably modify the fetch commands to only fetch what we really need but it is a pain to work with shallow repositories since certain things done with the history will just fail in some situations and executing multiple fetches for every user is probably slowing down things more.

what about an arbitrarily large but still much smaller than the whole repository amount?

for example, fetching only the last 10000 commits?

waiting 10 minutes is still a lot better than waiting 2 hours, and people using a shallow clone are likely to have a a slow network connection anyways.