Better exception

[ari]

After spending an hour trying to figure out why I had a key error in an orchestration state I realised that saltstack requires a runner id with a dot. A clearer error message will save the next person wasting the same time.

What does this PR do?

Improve error message.

[rallytime]

Thank you for submitting this change @ari. That will be helpful for other users.

Can you submit this against the 2017.7 branch? The 2017.7.2 branch is closed for contributions at this time.

[cachedout]

I would actually vote for the develop branch on this.

[ari]

I'm happy if you want to copy this commit anywhere that makes sense to you, or adjust it to suit the project styling better.

[rallytime]

@ari If you could move it to develop, that would be great. Thanks!

[cachedout]

I will close this for now. When it is moved to the new branch we will look at it there. Thanks.

[ari]

I refer to your own documentation here: https://docs.saltstack.com/en/latest/topics/development/contributing.html

If you're working on a bug or documentation fix, create your branch from the oldest release branch that contains the bug or requires the documentation update.

Clearly I've misunderstood your merge-forward policy or what constitutes documentation or feature, so rather than me navigating it or duplicating the entire pull request and commit (even though it is trivial) perhaps you'd like to just make a similar change to the code base wherever you choose. If not, no problem, I'm personally not likely to make this mistake again anyhow. This was just me trying to help out the next person.

[rallytime]

Hi @ari - Yes, we do typically like bug fixes in the oldest release branch. However, we also occasionally request that bug fixes to sensitive areas of the code be submitted to develop. That way we can reduce regression potential as the change can bake in develop before releasing.

In addition, we've recently added a new process with the year.month branches to also include a year.month.release-num branch which we're handling a bit differently to help with release stability. I've added some documentation here, specifically in the Main Release Branches and Dot Release Branches to help distinguish this, but any suggestions of how to make that more clear are welcome!