fix: derive all toolchain repo names from a single base name

[sallustfire]

When jq.bzl is consumed as a standalone bazel_dep, use_repo(toolchains, "jq") produces a @jq repo with a dangling symlink.

The _toolchains_extension creates platform repos with prefix jq_toolchains (e.g. jq_toolchains_linux_amd64), but jq_host_alias_repo(name = "jq") constructs its symlink using rctx.attr.name, targeting ../jq_linux_amd64/jq which doesn't exist.

This is masked when jq.bzl is consumed through aspect_bazel_lib, which creates platform repos with the jq prefix.

The fix introduces a single local variable in the extension from which all repo names are derived, so the platform repo prefix, the user_repository_name passed to jq_toolchains_repo, and the host alias name are always consistent.

bazel_dep(name = "jq.bzl", version = "0.6.0")
toolchains = use_extension("@jq.bzl//jq:extensions.bzl", "toolchains")
use_repo(toolchains, "jq", "jq_toolchains")
# @jq//:jq now resolves correctly

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Changes are visible to end-users: yes

• Searched for relevant documentation and updated as needed: no
• Breaking change (forces users to change their own code or config): no
• Suggested release notes appear below: yes

Fixed: jq_host_alias_repo now resolves correctly when jq.bzl is used as a standalone bazel_dep. Previously, use_repo(toolchains, "jq") produced a dangling symlink because the platform repos were named jq_toolchains_{platform} while the host alias expected jq_{platform}. Platform repos are now named jq_{platform} to match.

Test plan

• New test cases added
  • jq_host_alias_test exercises the @jq host alias repo via use_repo(toolchains, "jq"), verifying the symlink resolves and the binary executes

[aspect-workflows]

Bazel 7 (Test)

1 test target passed

Targets

//jq/tests:check_stamped [k8-fastbuild] 52ms

Total test execution time was 52ms. 11 tests (91.7%) were fully cached saving 803ms.

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Bazel 8 (Test)

1 test target passed

Targets

//jq/tests:check_stamped [k8-fastbuild] 66ms

Total test execution time was 66ms. 11 tests (91.7%) were fully cached saving 690ms.

---

Bazel 9 (Test)

1 test target passed

Targets

//jq/tests:check_stamped [k8-fastbuild] 82ms

Total test execution time was 82ms. 11 tests (91.7%) were fully cached saving 656ms.

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Bazel 7 (Test)

e2e/smoke

All tests were cache hits

3 tests (100.0%) were fully cached saving 111ms.

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Bazel 8 (Test)

e2e/smoke

All tests were cache hits

3 tests (100.0%) were fully cached saving 158ms.

---

Bazel 9 (Test)

e2e/smoke

All tests were cache hits

3 tests (100.0%) were fully cached saving 180ms.

[sallustfire]

@alexeagle Any chance you or someone else can look at what's hopefully an innocuous bugfix or at least make sure it doesn't get lost in the rennovate backlog?