go1.21 support

[ldez]

This PR is to evaluate and prepare golangci-lint to go1.21.

This PR will evolve during the beta and RC phases of go1.21.

[ldez]

For now, there is a problem with go-critic, I will investigate to understand the problem.

Edit: I tested to run tests of go-critic itself with go1.21 and the problem is also here.
I don't know if it's a bug of go1.21 or a problem with go-critic/ruleguard.
go-critic/go-critic#1349
quasilyte/go-ruleguard#449

[pohly]

As mentioned on Slack: if Go 1.21rc2 is installed in a module, gocritic: load embedded ruleguard rules: rules/rules.go:13: can't load fmt: setting an explicit GOROOT can fix this problem. occurs again.

[ldez]

I disabled ruleguard (one "rule" inside gocritic), only with go1.21, I think it's the best move to be able to create a release quickly.

Note: the Go version should be 1.21 inside go.mod or be defined inside the run section:

go.mod

module your/module/name

go 1.21

//...

.golangci.yml

run:
    go: '1.21'

CLI flags

--go=1.21

[SVilgelm]

LGTM

[pohly]

Disabling ruleguard does not fix the problem in Kubernetes.

I first tried a config change:

linters-settings:
  gocritic:
    disabled-checks:
      - ruleguard               # unused

Then I bumped the golangci-lint in Kubernetes to ldez:feat/go1.21 and also still got the same problem:

ERROR: level=warning msg="plugin: 'AnalyzerPlugin' plugins are deprecated, please use the new plugin signature: https://golangci-lint.run/contributing/new-linters/#create-a-plugin"
ERROR: level=error msg="[linters_context] gocritic: load embedded ruleguard rules: rules/rules.go:13: can't load fmt: setting an explicit GOROOT can fix this problem."

If I had to guess, I would say that gocritic loads ruleguard rules regardless whether the ruleguard check is enabled or not (haven't checked).

[ldez]

@pohly From my memories, the problem was already here before go1.21.

If I had to guess, I would say that gocritic loads ruleguard rules regardless whether the ruleguard check is enabled or not (haven't checked).

The load of the embedded rules is done when gocritic is enabled.

golangci-lint/pkg/golinters/gocritic.go

Line 92 in 29f9717

err := checkers.InitEmbeddedRules()

[pohly]

Right, I also just found that. So to me it looks like all of gocritic is broken for Kubernetes because of this problem.

[pohly]

Disabling gocritic entirely makes golangci-lint usable with 1.21 in Kubernetes, but that would be a pity.

[pohly]

From my memories, the problem was already here before go1.21.

There was a different problem with having the Go toolchain inside the Go package. That got solved. Now go1.21 broke that again, with no solution so far.

[ldez]

Have you tried with go-critic itself (standalone CLI)?

[pohly]

go-critic works with go1.20.4 and go1.21rc4 when those are installed outside of Kubernetes. It also works with _output/local/.gimme/versions/go1.21rc3.linux.amd64/bin inside the Kubernetes repo but only if go-critic was compiled with go1.20.4.

However, go-critic fails once it is compiled with go1.21rc3, no matter where the Go installation is located when invoking it. I'm a bit surprised by that because I thought I had seen a difference before when trying it with golangi-lint - perhaps I had made a mistake when testing.

[ldez]

I would like to propose moving this discussion outside of this PR, maybe on Slack.

EDIT: after discussing on the Gopher Slack, we decided to open an issue on the go-critic repo: go-critic/go-critic#1359

[Dasio]

Just FYI regarding https://github.com/golangci/golangci-lint/pull/3922/files#diff-15c806aa509538190832852f439e9921a23bec2da81f95ed0e4bf13c14e5b160R44

With latest version it is still built with 1.20

golangci-lint run --version
golangci-lint has version 1.54.1 built with go1.20.7 from a9378d9 on 2023-08-11T10:14:36Z

Because of this I got errors such as

../../../../../../../../opt/homebrew/Cellar/go/1.21.0/libexec/src/slices/sort.go:67:7: undefined: min (typecheck)
		m = min(m, x[i])

It's fixed if I compile it myself using go1.21

[ldez]

Just FYI regarding https://github.com/golangci/golangci-lint/pull/3922/files#diff-15c806aa509538190832852f439e9921a23bec2da81f95ed0e4bf13c14e5b160R44

This line is to run some tests with the previous version of golangci-lint.
It's not related to the build.

The build use go1.21:

golangci-lint/.github/workflows/tag.yml

Line 19 in ed8eb4e

go-version: '1.21'

In your log I can see opt/homebrew/Cellar/, I guess you are on Darwin, and maybe you are using Brew: Brew doesn't use our binary, it built the binary so it depends on how Brew built it.

The official binaries:

$ golangci-lint version
golangci-lint has version 1.54.1 built with go1.21.0 from a9378d9b on 2023-08-11T12:49:16Z

[Dasio]

Oh, you are right, I'm sorry, thanks