Add support for git shallow clones

[sbuzonas]

When working with a large repository it would be nice to opt for a clone depth of 1 to still leverage git to patch dependencies for a project

[stof]

the issue with a clone depth of 1 is that the locked commit may not be the latest commit of the repo. If the depth is not high enough to reach the locked commit, the installation will not work. And there is no way to find a value of depth working everywhere (it is easy to create a case requiring more than this value: just add more commit after the locked one in the repo)

[sbuzonas]

A similar state to a shallow clone can be to git init, set remote, fetch desired sha.

[GromNaN]

Interesting idea @slbmeh. That would avoid limitations of shallow clones. Do you know the command to run to fetch only the desired commit ?

[sbuzonas]

@GromNaN you can fetch any treeish object so just fetch the hash directly

[sbuzonas]

actually, it doesn't appear to work like that anymore... i'll do further investigation, i was sure it worked for me like that git 1.6 era or so... there's a way to do it with the plumbing rather than the porcelain commands

[Seldaek]

Please check #4961

[shqear93]

any updates on this?

[Seldaek]

I think this isn't as needed anymore now that we clone from the cache dir, so we do local clones which are pretty fast.

[hetii]

This issue should be reopened. For CI/CD purpose or docker/kubernetes world where we start always from clean scratch there is no shared cache and for more complex project it's a waste of time to get all full repositories instead what is needed.

[ondrejmirtes]

@hetii Wouldn’t your problem be solved with --prefer-dist?

[hawkeyetwolf]

@ondrejmirtes yes indeed --prefer-dist should do it, but in my case the private packagist wasn't making the dist output available. I'm still working on that, but here's some thoughts for others:

If your private packagist isn't building dist output, see docs here.

If your private packagist is mirroring a private GitHub (or BitBucket?) instance, you may just need to edit your private packagist's satis.json and change the repository type from vcs to github (or git-bitbucket) to force Composer into making dist available from those services. You may need to clear your composer cache for this to start working. Details here.