refs for external skaffold dependencies

[maxplumley]

Hi folks,

Loving Skaffold, thanks for all the hard work on this!

I've been messing around with external configurations hosted in git repositories and wondering if there were more options for pining a dependency to something like a tag, rather than just the git branch. I noticed that there are a number of closed issues such as #7018 and #9430, which suggest that it's possible to pass a commit SHA to git.ref - I've given this a shot and it doesn't appear to be working. Just wondering if I'm missing something here - this seems like a really great enhancement.

Things I've tried:

I've created a simple configuration that reproduces the issue here

setting ref to a commit SHA

requires:
  - git:
      repo: https://github.com/maxplumley/skaffold-external.git
      path: skaffold.yaml
      ref: e919f57aae48bdb69c262dd26093a2debd433518

and running skaffold dev, results in this error

parsing skaffold config: error parsing skaffold configuration file: caching remote dependency https://github.com/maxplumley/skaffold-external.git: failed to clone repo: running [/opt/homebrew/bin/git clone https://github.com/maxplumley/skaffold-external.git ./eMqefSnXMmhKzHNfWBPPEaZGg22-V7Bo --branch e919f57aae48bdb69c262dd26093a2debd433518 --depth 1]
 - stdout: ""
 - stderr: "Cloning into './eMqefSnXMmhKzHNfWBPPEaZGg22-V7Bo'...\nfatal: Remote branch e919f57aae48bdb69c262dd26093a2debd433518 not found in upstream origin\n"
 - cause: exit status 128

using Skaffold v2.16.1