Starlark seems to be overwhelmingly bound to Bazel at the moment—searching for it, I had to follow a link from Bazel to the GitHub repo and then from there I got to the implementations and found this:
> The implementations below are not fully compliant to the specification yet. We aim to remove the differences and provide a common test suite.
This does not inspire confidence that I could use this in a project any time soon.
Meanwhile, from what I can tell Pkl has a single Truffle implementation that currently supports 4 languages, it has a syntax that is more familiar to me as a non-Python dev, it has static typing, and it has a dedicated plugin in most IDEs (whereas Starlark just says to install the Bazel plugin). Maybe Starlark is more appealing to people writing Python or already using Bazel, but for the rest of us there's no contest right now.
Never used Bazel in my life, so while I can appreciate your passion, I guess I don't share your perspective. Generally the pattern I've seen has been providing a skylark interface to allow folks to define rules or configurations, which are then consumed through by whatever service via starlark-rust or similar implementations.
Step two of installing Copybara is to install Bazel [0], so that doesn't exactly contradict my claim that if you're not already using Bazel you probably won't use Starlark.
> Copybara doesn't have a release process yet, so you need to compile from HEAD.
Looks like there's an Arch Linux build maintained by... somebody, but if you're not on Arch then you're going to be building Copybara with Bazel. That this works for them suggests to me that their community has a significant amount of overlap with the Bazel community, so it's not good evidence of Starlark being used outside of the Bazel world.
Lots of projects developed at Google use Starlark. Copybara is one of them. That's where the connection comes from.
Many other companies are also adopting Starlark for their own needs. For example, Meta has invested a lot in Starlark and published their implementation (https://developers.facebook.com/blog/post/2021/04/08/rust-st...), although they don't use Bazel at all.
Starlark was first created for Bazel. The organic user growth comes from people who have seen and used the language, so often Bazel users. But it doesn't have to be.
> The implementations below are not fully compliant to the specification yet. We aim to remove the differences and provide a common test suite.
This does not inspire confidence that I could use this in a project any time soon.
Meanwhile, from what I can tell Pkl has a single Truffle implementation that currently supports 4 languages, it has a syntax that is more familiar to me as a non-Python dev, it has static typing, and it has a dedicated plugin in most IDEs (whereas Starlark just says to install the Bazel plugin). Maybe Starlark is more appealing to people writing Python or already using Bazel, but for the rest of us there's no contest right now.