I missed this on my first attempt to write this document. Consequently
we're currently depending on a version of HCL which uses Unicode 9, and
that's significantly lagging behind everything else which is currently on
Unicode 13.
My goal of adding these docs then is to remind us to update HCL to Unicode
15 once we're updating everything else to Unicode 15 with the Go 1.20
release, assuming that the Go team completes that Unicode upgrade as
currently planned.
Previously this is a task that I've just taken on using my own knowledge
of how these parts fit together, but that's not at all a sustainable
situation, and so here I've just documented the steps I've followed in for
previous Unicode version upgrades, and thus which I'd expect to follow
for future Unicode version upgrades too.
I hope this is also a somewhat-interesting overview of how Terraform makes
use of Unicode, even for folks who are just working on the other relevant
features of Terraform and not specifically trying to change Terraform's
Unicode support.
Since I'm the primary maintainer of two of the dependencies involved in
this it seems likely that following this process will still involve me
in _some_ capacity, but hopefully only necessarily in the form of
reviewing PRs and cutting new releases of those libraries.