imported but not used (typecheck)

[zhaoyunxing92]

Welcome

• Yes, I'm using a binary release within 2 latest major releases. Only such installations are supported.
• Yes, I've searched similar issues on GitHub and didn't find any.
• Yes, I've included all information below (version, config, etc).
• Yes, I've tried with the standalone linter if available. (https://golangci-lint.run/usage/linters/)

Description of the problem

typecheck linter reports false positive errors on imports for packages which have name different from the module name.

Version of golangci-lint

$ golangci-lint --version
# Paste output here
1.41.1

Configuration file

$ cat .golangci.yml
# paste output here
linters-settings:
  govet:
    check-shadowing: true
  golint:
    min-confidence: 0
  gocyclo:
    min-complexity: 10
  maligned:
    suggest-new: true
  dupl:
    threshold: 100
  goconst:
    min-len: 2
    min-occurrences: 2
  depguard:
    list-type: blacklist
    packages:
      # logging is allowed only by logutils.Log, logrus
      # is allowed to use only in logutils package
      - github.com/sirupsen/logrus
  misspell:
    locale: US
  lll:
    line-length: 140
  goimports:
    local-prefixes: github.com/golangci/golangci-lint
  gocritic:
    enabled-tags:
      - performance
      - style
      - experimental
    disabled-checks:
      - wrapperFunc

linters:
  disable-all: true
  enable:
    - govet
    - staticcheck
    - ineffassign
    - misspell

run:
  skip-dirs:
    - test/testdata_etc
    - pkg/golinters/goanalysis/(checker|passes)

issues:
  exclude-rules:
    - text: "weak cryptographic primitive"
      linters:
        - gosec
    - linters:
        - staticcheck
      text: "SA1019:"

# golangci.com configuration
# https://github.com/golangci/golangci/wiki/Configuration
service:
  golangci-lint-version: 1.15.x # use the fixed version to not introduce new linters unexpectedly
  prepare:
    - echo "here I can run custom commands, but no preparation needed for this repo"

Go environment

$ go version && go env
# paste output here
1.13

GO111MODULE=""
  GOARCH="amd64"
  GOBIN=""
  GOCACHE="/home/runner/.cache/go-build"
  GOENV="/home/runner/.config/go/env"
  GOEXE=""
  GOFLAGS=""
  GOHOSTARCH="amd64"
  GOHOSTOS="linux"
  GONOPROXY=""
  GONOSUMDB=""
  GOOS="linux"
  GOPATH="/home/runner/go"
  GOPRIVATE=""
  GOPROXY="[https://proxy.golang.org,direct](https://proxy.golang.org%2Cdirect/)"
  GOROOT="/opt/hostedtoolcache/go/1.13.15/x64"
  GOSUMDB="sum.golang.org"
  GOTMPDIR=""
  GOTOOLDIR="/opt/hostedtoolcache/go/1.13.15/x64/pkg/tool/linux_amd64"
  GCCGO="gccgo"
  AR="ar"
  CC="gcc"
  CXX="g++"
  CGO_ENABLED="1"
  GOMOD=""
  CGO_CFLAGS="-g -O2"
  CGO_CPPFLAGS=""

Verbose output of running

$ golangci-lint cache clean
$ golangci-lint run -v
# paste output here

Run golangci-lint run --timeout=10m -v
level=info msg="[config_reader] Config search paths: [./ /home/runner/work/dubbo-go/dubbo-go /home/runner/work/dubbo-go /home/runner/work /home/runner /home /]"
level=info msg="[config_reader] Used config file .golangci.yml"
level=info msg="[lintersdb] Active 4 linters: [govet ineffassign misspell staticcheck]"
level=info msg="[loader] Go packages loading at mode 575 (deps|exports_file|name|types_sizes|compiled_files|files|imports) took 2m10.555005976s"
level=info msg="[runner/filename_unadjuster] Pre-built 0 adjustments in 56.346[8](https://github.com/apache/dubbo-go/runs/6475077184?check_suite_focus=true#step:8:8)18ms"
level=info msg="[linters context/goanalysis] analyzers took 1m50.437648188s with top 10 stages: buildir: 1m31.46[9](https://github.com/apache/dubbo-go/runs/6475077184?check_suite_focus=true#step:8:9)77433s, nilness: 7.131271175s, inspect: 2.552770752s, fact_deprecated: 1.464938398s, ctrlflow: 1.464382999s, printf: 1.128907497s, fact_purity: 987.689019ms, typedness: 947.686229ms, SA5012: 634.748186ms, misspell: 317.228465ms"
level=info msg="[runner/skip dirs] Skipped 15 issues from dir protocol/grpc/protoc-gen-dubbo/examples by pattern (^|/)examples($|/)"
Error: remoting/etcdv3/listener.go:[10](https://github.com/apache/dubbo-go/runs/6475077184?check_suite_focus=true#step:8:10)1:45: undeclared name: `clientv3` (typecheck)
level=info msg="[runner] Issues before processing: 238, after processing: 2"
level=info msg="[runner] Processors filtering stat (out/in): max_from_linter: 2/2, sort_results: 2/2, autogenerated_exclude: 208/223, exclude-rules: 199/208, max_per_file_from_linter: 2/2, path_prefixer: 2/2, skip_dirs: 223/238, nolint: 198/199, uniq_by_line: 2/198, diff: 2/2, source_code: 2/2, path_shortener: 2/2, path_prettifier: 238/238, skip_files: 238/238, identifier_marker: 208/208, exclude: 208/208, max_same_issues: 2/2, severity-rules: 2/2, cgo: 238/238, filename_unadjuster: 238/238"
level=info msg="[runner] processing took 15.32565ms with stages: exclude-rules: 7.847936ms, identifier_marker: 4.545552ms, nolint: 1.8004ms, path_prettifier: 413.823µs, autogenerated_exclude: 313.817µs, skip_dirs: 227.8[12](https://github.com/apache/dubbo-go/runs/6475077184?check_suite_focus=true#step:8:12)µs, filename_unadjuster: 54.403µs, source_code: 47.303µs, cgo: 46.003µs, uniq_by_line: 15.901µs, max_same_issues: 4.3µs, max_per_file_from_linter: 2.2µs, path_shortener: 2.1µs, max_from_linter: 1.9µs, exclude: 600ns, diff: 500ns, skip_files: 400ns, severity-rules: 300ns, sort_results: 300ns, path_prefixer: 100ns"
level=info msg="[runner] linters took 1m5.429969576s with stages: goanalysis_metalinter: 1m5.4[14](https://github.com/apache/dubbo-go/runs/6475077184?check_suite_focus=true#step:8:14)485817s"
level=info msg="File cache stats: 506 entries of total size 2.0MiB"
level=info msg="Memory: 1962 samples, avg is 396.8MB, max is 1491.6MB"
func (l *EventListener) handleEvents(event *clientv3.Event, listeners ...remoting.DataListener) bool {
                                            ^
level=info msg="Execution took 3m16.059640818s"
Error: remoting/etcdv3/listener.go:31:2: "go.etcd.io/etcd/client/v3" imported but not used (typecheck)
	"go.etcd.io/etcd/client/v3"
	^
Error: Process completed with exit code 1.

Code example or link to a public repository

// add your code here

https://github.com/apache/dubbo-go/blob/6960942bf45c8d5a5e5e7fa5a46edf26aef6337e/remoting/etcdv3/listener.go#L31

https://github.com/apache/dubbo-go/blob/6960942bf45c8d5a5e5e7fa5a46edf26aef6337e/remoting/etcdv3/listener.go#L101

#L31

#L101

[boring-cyborg[bot]]

Hey, thank you for opening your first Issue ! 🙂 If you would like to contribute we have a guide for contributors.

[ldez]

Hello,

I don't reproduce your problem:

$ go version                                        
go version go1.17.10 linux/amd64
$ golangci-lint version            
golangci-lint has version 1.46.1 built from 044f0a17 on 2022-05-12T09:23:45Z
$ git clone [email protected]:apache/dubbo-go.git       
Cloning into 'dubbo-go'...
remote: Enumerating objects: 49874, done.
remote: Counting objects: 100% (46/46), done.
remote: Compressing objects: 100% (35/35), done.
remote: Total 49874 (delta 17), reused 22 (delta 10), pack-reused 49828
Receiving objects: 100% (49874/49874), 86.32 MiB | 14.69 MiB/s, done.
Resolving deltas: 100% (31473/31473), done.
$ cd ./dubbo-go
$ golangci-lint run -v --timeout=5m
INFO [config_reader] Config search paths: [./ /home/ldez/sources/experimental/dubbo-go /home/ldez/sources/experimental /home/ldez/sources /home/ldez /home /] 
INFO [config_reader] Used config file .golangci.yml 
INFO [lintersdb] Active 4 linters: [govet ineffassign misspell staticcheck] 
INFO [loader] Go packages loading at mode 575 (exports_file|files|types_sizes|compiled_files|deps|imports|name) took 1.801636414s 
INFO [runner/filename_unadjuster] Pre-built 0 adjustments in 41.27123ms 
INFO [linters context/goanalysis] analyzers took 0s with no stages 
INFO [runner] Issues before processing: 169, after processing: 0 
INFO [runner] Processors filtering stat (out/in): skip_files: 169/169, identifier_marker: 88/88, filename_unadjuster: 169/169, path_prettifier: 169/169, cgo: 169/169, skip_dirs: 169/169, exclude-rules: 1/88, nolint: 0/1, autogenerated_exclude: 88/169, exclude: 88/88 
INFO [runner] processing took 6.346761ms with stages: identifier_marker: 2.874326ms, autogenerated_exclude: 1.03393ms, path_prettifier: 774.345µs, nolint: 619µs, exclude-rules: 549.199µs, skip_dirs: 448.873µs, cgo: 34.563µs, filename_unadjuster: 7.77µs, max_same_issues: 1.485µs, uniq_by_line: 469ns, exclude: 379ns, skip_files: 356ns, diff: 353ns, max_from_linter: 327ns, source_code: 276ns, max_per_file_from_linter: 258ns, path_shortener: 244ns, sort_results: 231ns, severity-rules: 221ns, path_prefixer: 156ns 
INFO [runner] linters took 254.429781ms with stages: goanalysis_metalinter: 247.923216ms 
INFO File cache stats: 0 entries of total size 0B 
INFO Memory: 22 samples, avg is 62.1MB, max is 135.8MB 
INFO Execution took 2.103353669s

typecheck is not a real linter it's just a way to parse/display "compilation" and linters errors (linter reports are not errors).

My recommendations:

• run the following command: go mod tidy
• use a supported Go version: 1.17 or 1.18
• use the latest version of golangci-lint

[zhaoyunxing92]

Because PR1898 has not been merged, you can change a repository。I can reproduce it locally。

➜  dubbo-go git:(update-etcd) go version
go version go1.17 darwin/amd64

➜  dubbo-go git:(update-etcd) golangci-lint --version
golangci-lint has version v1.44.2 built from (unknown, mod sum: "h1:MzvkDt1j1OHkv42/feNJVNNXRFACPp7aAWBWDo5aYQw=") on (unknown)

git clone git@github.com:zhaoyunxing92/dubbo-go.git

git checkout update-etcd

➜  dubbo-go git:(update-etcd) golangci-lint run -v --timeout=5m
INFO [config_reader] Config search paths: [./ /Users/docker/code/github/go/dubbo-go /Users/docker/code/github/go /Users/docker/code/github /Users/docker/code /Users/docker /Users /]
INFO [config_reader] Used config file .golangci.yml
INFO [lintersdb] Active 4 linters: [govet ineffassign misspell staticcheck]
INFO [loader] Go packages loading at mode 575 (deps|exports_file|files|name|compiled_files|imports|types_sizes) took 1.548617925s
INFO [runner/filename_unadjuster] Pre-built 0 adjustments in 16.297701ms
INFO [linters context/goanalysis] analyzers took 3m2.57163835s with top 10 stages: buildir: 1m53.577385135s, nilness: 15.488317981s, inspect: 5.634983476s, fact_deprecated: 4.239221392s, ctrlflow: 3.877627053s, printf: 3.576713362s, fact_purity: 3.275427578s, typedness: 2.983872509s, SA5012: 2.27950413s, misspell: 1.019647117s
INFO [runner/skip dirs] Skipped 15 issues from dir protocol/grpc/protoc-gen-dubbo/examples by pattern (^|/)examples($|/)
INFO [runner] Issues before processing: 238, after processing: 2
INFO [runner] Processors filtering stat (out/in): path_prettifier: 238/238, nolint: 198/199, path_prefixer: 2/2, identifier_marker: 208/208, max_per_file_from_linter: 2/2, max_same_issues: 2/2, source_code: 2/2, severity-rules: 2/2, filename_unadjuster: 238/238, skip_files: 238/238, exclude: 208/208, uniq_by_line: 2/198, diff: 2/2, path_shortener: 2/2, sort_results: 2/2, cgo: 238/238, skip_dirs: 223/238, autogenerated_exclude: 208/223, exclude-rules: 199/208, max_from_linter: 2/2
INFO [runner] processing took 8.376519ms with stages: exclude-rules: 3.595038ms, identifier_marker: 2.643842ms, nolint: 1.004459ms, path_prettifier: 540.514µs, autogenerated_exclude: 321.141µs, skip_dirs: 159.927µs, source_code: 63.679µs, cgo: 13.698µs, uniq_by_line: 12.438µs, filename_unadjuster: 10.608µs, skip_files: 3.278µs, max_same_issues: 2.933µs, path_shortener: 1.365µs, max_from_linter: 1.224µs, max_per_file_from_linter: 986ns, diff: 385ns, exclude: 381ns, severity-rules: 247ns, sort_results: 245ns, path_prefixer: 131ns
INFO [runner] linters took 18.305281308s with stages: goanalysis_metalinter: 18.296632484s
remoting/etcdv3/listener.go:101:45: undeclared name: `clientv3` (typecheck)
func (l *EventListener) handleEvents(event *clientv3.Event, listeners ...remoting.DataListener) bool {
                                            ^
remoting/etcdv3/listener.go:31:2: "go.etcd.io/etcd/client/v3" imported but not used (typecheck)
	"go.etcd.io/etcd/client/v3"
	^
INFO File cache stats: 506 entries of total size 2.0MiB
INFO Memory: 178 samples, avg is 1385.6MB, max is 2285.8MB
INFO Execution took 19.882963404s

[zhaoyunxing92]

must import through an alias to pass the check

[ldez]

your PR doesn't compile because of a problem with the google.golang.org/grpc version.

[zhaoyunxing92]

That's not the grpc problem. I solved it with aliases，You can see my exception log. It does exist

[volker-raschek]

Hi, I have a similar problem.

I use the container image golangci/golangci-lint:v1.46.1-alpine for liniting the source code in the CI. I receive the following errors:

database/database_test.go:20:62: undeclared name: `dockerutil` (typecheck)
func requireCountNetworks(ctx context.Context, dockerClient *dockerutil.Client, dbOptions *database.DbOptions, equal int, t *testing.T) {
                                                             ^
database/database_test.go:27:80: undeclared name: `dockerutil` (typecheck)
func requireContainerHasNetworksAndAliasses(ctx context.Context, dockerClient *dockerutil.Client, dbOptions *database.DbOptions, t *testing.T) {
                                                                               ^
database/database_test.go:10:2: "github.com/dedalus-cis4u/dockerutil/v6" imported but not used (typecheck)
        "github.com/dedalus-cis4u/dockerutil/v6"

The lib contains /v6 at the end of the import path:

import (
	"context"
	"database/sql"
        ....

	"github.com/dedalus-cis4u/dockerutil/v6"
)

If I execute the golangci-lint locally it works fine.

markus@markus-pc:~/workspace/testutils (master *=)$ make golangci-lint 
golangci-lint run --concurrency=24

Unfortunately, it is not possible to share the source code of the project publicly. If there are any questions, I may be able to answer them through individual snippets.

[ldez]

Hi,

typecheck is not a real linter it's just a way to parse/display "compilation" and linters errors (linter reports are not errors).

So you have to check if your code build.

[volker-raschek]

Hi @ldez,
it is a shared go library and no program. All of the tests are successfully. I tried to disable the typecheck for the CI, but this seems not to work with the following config. I receive the same error.

run:
  skip-dirs:
  - it
  timeout: 10m
  tests: true

linters:
  disable-all: true
  enable:
  # Default
  - deadcode
  - errcheck
  - gosimple
  - govet
  - ineffassign
  - staticcheck
  - structcheck
  # - typecheck
  - unused
  - varcheck

  # Additionally linters
  - containedctx
  - decorder
  - errname
  - errorlint
  - gosec
  - ireturn
  - makezero
  - misspell
  - unparam
  - whitespace
  - wrapcheck

[ldez]

typecheck is not a real linter it's just a way to parse/display "compilation" and linters errors (linter reports are not errors), typecheck cannot be disabled because of that.
All the linters can trigger a typecheck issue, but some linters require that the code compile, those linters will produce more typecheck issues.

[Integralist]

I'm also seeing this issue:

"net/url" imported but not used typecheck [9, 2]
"github.com/sethvargo/go-retry" imported but not used typecheck [25, 2]

I really wouldn't expect any of the linters I have enabled to complain about the go standard library net/url package like this.

Additionally, even if I update the import path to appease the linter (e.g.url "net/url") it still thinks the package isn't used when I have if urlErr, ok := err.(*url.Error); ok && urlErr.Timeout() {...} in my code file.

Is there a way to know which one of the linters is reporting this typecheck warning? It's rather annoying to see this warning message in my IDE whilst working on a code base.

Thanks.

[advoretsky]

I have the same issue: "net/url" imported and not used (typecheck)
despite that down the code there is "url.QueryEscape"

my code doesn't even redefine "url" to possibly confuse linter. Only 2 appearances of "url" in the package are mentioned above
build and tests pass

[ldez]

typecheck is not a linter, it's just a way to identify, parse, and display compiling errors and some linter errors (errors are not issue reports).

https://golangci-lint.run/welcome/faq/#why-do-you-have-typecheck-errors

If you are facing the same problem, the best way to contribute is to provide the following information:

A reproducible example or link to a public repository.

golangci-lint --version

cat .golangci.yml

go version && go env

golangci-lint cache clean
golangci-lint run -v