jsonnet_go_dependencies() fails if go toolchain has already been registered

[glindstedt]

In this commit 1b7cbff jsonnet_go_dependencies() was modified to pass a version parameter to go_register_toolchains(). If a go toolchain has already been registered it results in this error:

Error in fail: go_register_toolchains: version set after go sdk rule declared (go_sdk)

And according to the docs, setting a version is disallowed if a toolchain has already been registered: https://github.com/bazelbuild/rules_go/blob/master/go/toolchains.rst#go-register-toolchains

[sparkprime]

I wonder if the ability to not set version requires a recent version of bazel?

[jmthvt]

As per bazelbuild/rules_go#2761 (comment), go_register_toolchains can be called with no version set if go_download_sdk is called first.

[anguslees]

Passing an explicit None seems to be a reasonable workaround:

go_register_toolchains()

load("@google_jsonnet_go//bazel:deps.bzl", "jsonnet_go_dependencies")
jsonnet_go_dependencies(go_sdk_version = None)