Bazel 8.0.0rc1: 'cc/toolchains' is not a package error

[gergelyfabian]

Description of the bug:

Testing Bazel 8.0.0rc1 I got such an error:

ERROR: Error computing the main repository mapping: at /home/user/.cache/bazel/_bazel_user/64527517dacf7170f7d914889f83481c/external/bazel_tools/tools/cpp/cc_configure.bzl:18:6: Label '@@rules_cc//cc/toolchains:toolchain_config_utils.bzl' is invalid because 'cc/toolchains' is not a package; perhaps you meant to put the colon here: '@@rules_cc//cc:toolchains/toolchain_config_utils.bzl'?

This worked with Bazel 7.3.2.

Which category does this issue belong to?

No response

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

Reproduction: https://github.com/gergelyfabian/bazel-scala-example/tree/bazel-8.0.0rc1

Simply run bazel build //... in this repo at branch bazel-8.0.0rc1

Which operating system are you running Bazel on?

Ubuntu 24.04

What is the output of bazel info release?

release 8.0.0rc1

If bazel info release returns development version or (@non-git), tell us how you built Bazel.

No response

What's the output of git remote get-url origin; git rev-parse HEAD ?

git@github.com:gergelyfabian/bazel-scala-example.git
0bbacfe5f35550db2da2ea5ba4f0edcba81ad46

If this is a regression, please try to identify the Bazel commit where the bug was introduced with bazelisk --bisect.

$ bazelisk --bisect=7.3.2..8.0.0rc1

This finds another bug:

ERROR: Error computing the main repository mapping: Label '@@platforms//host:extension.bzl' is invalid because 'host' is not a package; perhaps you meant to put the colon here: '@@platforms//:host/extension.bzl'?

first bad commit is 74c8ca4

But this is incorrect I think.

Have you found anything relevant by searching the web?

No response

Any other information, logs, or outputs that you want to share?

No response

[gergelyfabian]

Can be reproduced with 8.0.0rc2

[fmeum]

Could you check what happens if you manually add a recent version of rules_cc to the top of WORKSPACE?

[gergelyfabian]

Sure thing. I was just thinking about that in fact.

[gergelyfabian]

It seems rules_scala is including the following rules_cc version in my case:

$ bazel query --output=build //external:rules_cc
Starting local Bazel server and connecting to it...
# /home/user/Work/traveltime-platform/WORKSPACE:66:18
http_archive(
  name = "rules_cc",
  generator_name = "",
  generator_function = "rules_scala_setup",
  urls = ["https://github.com/bazelbuild/rules_cc/releases/download/0.0.6/rules_cc-0.0.6.tar.gz"],
  sha256 = "3d9e271e2876ba42e114c9b9bc51454e379cbf0ec9ef9d40e2ae4cec61a31b40",
  strip_prefix = "rules_cc-0.0.6",
)
# Rule rules_cc instantiated at (most recent call last):
#   /home/user/Work/my-projest/WORKSPACE:66:18                                                                                                  in <toplevel>
#   /home/user/.cache/bazel/_bazel_user/7f83a0b1f0940f88aec1f4530f927169/external/io_bazel_rules_scala/scala/private/macros/scala_repositories.bzl:96:21 in rules_scala_setup
# Rule http_archive defined at (most recent call last):
#   /home/user/.cache/bazel/_bazel_user/7f83a0b1f0940f88aec1f4530f927169/external/bazel_tools/tools/build_defs/repo/http.bzl:387:31 in <toplevel>

[fmeum]

That's too old. Without Bzlmod, it's next to impossible for Bazel to force newer versions of ruleset repos, so I would consider this (unfortunately) WAI and a reminder of what Bzlmod will give us.