Make git a dependency optional

[hoshsadiq]

Just tried this out as I'm trying to build a VM with minimal dependencies with runc and containerd et al (i.e. without docker).

While trying to run img to build an image, it failed due to git not being installed. Is there a reason for git being a requirement?

# img build -t x11 .
Building docker.io/library/test:latest
Setting up the rootfs... this may take a bit.
[+] Building 0.0s (0/0)
creating worker failed: failed to find git binary: exec: "git": executable file not found in $PATH

Would be nice to make this optional.

[unkaktus]

AFAIK buildkit itself depends on git binary and not img.

[AkihiroSuda]

PR: moby/buildkit#737

[hoshsadiq]

Can this be closed now that buildkit has it merged?

[AkihiroSuda]

Not vendored yet

[AkihiroSuda]

closing via #221