Is this a request for help?: no

Is this a BUG REPORT or FEATURE REQUEST? (choose one): FEATURE REQUEST

Version of Helm and Kubernetes: helm 3.4.0

What happened:

When running ct list-changed with the default target-branch (master) - if master does not exist (i.e. GitHub now defaults to main), then you get the following in GitHub Actions (via the chart-testing-action):

Error: Error running process: exit status 128

This is very tricky to debug without a dev environment that mirrors the GitHub Action (unfortunately I had a master branch locally so things would not fail locally). Mirroring the GitHub Action environment is not trivial - a bit of logging or a cleaner error would go a long ways to making this easier to debug!

I eventually figured this out by reasoning from this issue: #186

What you expected to happen:

ERROR: `--target-branch=master` does not exist

(Or infer which branch should be referenced from the git repository)

How to reproduce it (as minimally and precisely as possible):

# in a git repo with no master branch
ct list-changed

Anything else we need to know: