invalid slice name error should clarify min valid length is 3

[polarathene]

This error confused me a bit at first, why was it invalid? Eventually I noticed a length of 3 characters for a slice key was successful. Looked up the source and the restriction appears to be due to a regex pattern constraint.

Perhaps in this case the error message could better indicate the failure was due to a minimum expected length?

$ chisel find --release /opt/chisel-release base-distroless
2024/09/11 04:48:18 Processing /opt/chisel-release release...
error: invalid slice name "cc" in slices/base-distroless.yaml

chisel/internal/setup/setup.go

Lines 562 to 566 in ae52f84

	for sliceName, yamlSlice := range yamlPkg.Slices {
	match := snameExp.FindStringSubmatch(sliceName)
	if match == nil {
	return nil, fmt.Errorf("invalid slice name %q in %s", sliceName, pkgPath)
	}

chisel/internal/setup/setup.go

Lines 283 to 284 in ae52f84

	// snameExp matches only the slice name, without the leading package name.
	var snameExp = regexp.MustCompile(`^([a-z](?:-?[a-z0-9]){2,})$`)

[cjdcordeiro]

Thanks for suggesting this improvement @polarathene .

We'll keep this open for being picked up into our backlog ;)