No matching toolchains with experimental_repository_resolved_file

[keith]

Description of the problem / feature request:

When using the experimental_repository_resolved_file family of flags as recommended by this post, when using rules_go you end up with this error upon building:

ERROR: While resolving toolchains for target //lang:go_default_library: no matching toolchains found for types @io_bazel_rules_go//go:toolchain
ERROR: Analysis of target '//lang:go_default_library' failed; build aborted: no matching toolchains found for types @io_bazel_rules_go//go:toolchain

Note: this is an easy repro case with go, but I've also seen this with other toolchains:

ERROR: While resolving toolchains for target //tools/storyboarder:storyboarder: no matching toolchains found for types @bazel_tools//tools/cpp:toolchain_type

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

• Clone https://github.com/bazelbuild/buildtools
• Run bazel sync --experimental_repository_resolved_file=resolved.bzl
• Run bazel build --experimental_resolved_file_instead_of_workspace=resolved.bzl --experimental_repository_hash_file=resolved.bzl --experimental_verify_repository_rules=@bazel_tools//tools/build_defs/repo:git.bzl%git_repository --experimental_verify_repository_rules=@bazel_tools//tools/build_defs/repo:http.bzl%http_archive //...

(or add these flags to a .bazelrc)

What operating system are you running Bazel on?

macOS

What's the output of bazel info release?

release 0.26.0

Have you found anything relevant by searching the web?

No, I also can't really tell what the state of these flags is

[aiuto]

Given to both configurability (because toolchains) and ExternalDeps. I am not sure where the boundary is.

[katre]

This looks suspiciously similar to #7773, but I don't know what the --experimental_repository_resolved_file option is trying to do.

I suspect @aehlig may need to investigate this.

[aehlig]

I suspect @aehlig may need to investigate this.

tl;dr: fixed upstream

The longer story is the following. The repository resolved file was once faithfully representing the semantics of the of the WORKSPACE file as a flat value. But then, the tool chains were introduced as a new concept but not added to the resolved file. It took me a while to realize that, and once I did, I fixed it in 384fc0b. That commit didn't make it into 0.26, but will be in 0.27 (as the resolved file still is officially "experimental", that commit didn't justify a cherry-pick or a patch release).

[katre]

Thank you! Is there a separate commit adding support for register_execution_platforms?

[aehlig]

Thank you! Is there a separate commit adding support for register_execution_platforms?

Is that another feature added to WORKSAPCE files? Then I guess I'll have to add that to the resolved file as well.

[aehlig]

Pending for review: https://bazel-review.googlesource.com/c/bazel/+/102230