The nice thing though, if you are a developer, is that most of these providers code is open source. We've had cases where we've forked providers and fixed bugs on our own before we could get something merged in. I've personally fixed several provider bugs on my own out of annoyance - terraform's just a wrapper around cloud API's, usually, and you can be in control of how that works.
Yep, agreed, and IMHO in a lot of cases, as-is, terraform wouldn't be viable as a closed-source product. At least, I would have got frustrated and ditched it.
I haven't personally found a real bug in terraform or a provider yet, but I've had to refer to the source many times to figure out what is actually happening. It's always been either misuse on my part, or drift that the provider couldn't resolve.
I still consider it a failure though if it takes looking at source code to figure out what's actually going on -- whether it's vendor or in-house. The ironic and annoying part is it usually takes a deeper level of knowledge to write better error messages, but the people with that knowledge don't have the perception of it being a problem. I fight this battle internally with my own teams all the time. The problem is not getting people to make a change, but recognizing that the message is misleading/confusing/unclear to their users (eg: developers who are not domain experts like them) in the first place.
