Error: build flag -mod=readonly only valid when using modules

[lukasmalkmus]

Thank you for creating the issue!

• 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).

Please include the following information:

Version of golangci-lint

$ golangci-lint --version
golangci-lint has version v1.32.2 built from (unknown, mod sum: "h1:CgIeFWTLJ3Nt1w/WU1RO351j/CjN6LIVjppbJfI9nMk=") on (unknown)

Config file

$ cat .golangci.yml
run:
  modules-download-mode: readonly
  skip-dirs:
    - .git
    - .github
    - .vscode
    - bin
    - dist
    - docs
    - man
    - tools

linters:
  disable-all: true
  enable:
    - bodyclose
    - deadcode
    - dogsled
    - dupl
    - errcheck
    - exhaustive
    - exportloopref
    - goconst
    - gofmt
    - goimports
    - golint
    - gosec
    - gosimple
    - govet
    - ineffassign
    - misspell
    - nolintlint
    - prealloc
    - staticcheck
    - structcheck
    - stylecheck
    - typecheck
    - unconvert
    - unparam
    - unused
    - varcheck
    - whitespace

linters-settings:
  gofmt:
    simplify: true
  goimports:
    local-prefixes: github.com/lukasmalkmus/xxx
  govet:
    check-shadowing: true

Go environment

$ go version && go env
go version go1.15.4 darwin/amd64
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/lukasmalkmus/Library/Caches/go-build"
GOENV="/Users/lukasmalkmus/Library/Application Support/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/lukasmalkmus/Code/Go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/lukasmalkmus/Code/Go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/Cellar/go/1.15.4/libexec"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.15.4/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/lukasmalkmus/Code/Private/xxx/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/dy/s6dd70892l35f0444cwt96t40000gn/T/go-build856306592=/tmp/go-build -gno-record-gcc-switches -fno-common"

Verbose output of running

$ golangci-lint cache clean
$ golangci-lint run -v
INFO [config_reader] Config search paths: [./ /Users/lukasmalkmus/Code/Private/xxx /Users/lukasmalkmus/Code/Private /Users/lukasmalkmus/Code /Users/lukasmalkmus /Users /] 
INFO [config_reader] Used config file .golangci.yml 
INFO [lintersdb] Active 27 linters: [bodyclose deadcode dogsled dupl errcheck exhaustive exportloopref goconst gofmt goimports golint gosec gosimple govet ineffassign misspell nolintlint prealloc staticcheck structcheck stylecheck typecheck unconvert unparam unused varcheck whitespace] 
INFO [loader] Go packages loading at mode 575 (deps|exports_file|imports|name|types_sizes|compiled_files|files) took 12.275422ms 
ERRO Running error: context loading failed: failed to load packages: failed to load with go/packages: err: exit status 1: stderr: build flag -mod=readonly only valid when using modules 
INFO Memory: 2 samples, avg is 72.1MB, max is 72.1MB 
INFO Execution took 25.264712ms  

Build details above should be sufficient enough. TL;DR: latest macOS Catalina, golangci-lint 1.32.2

The error only occurs when using golang.org/x/tools v0.0.0-20201109182053-3db8fd265862. When downgrading to v0.0.0-20201022035929-9cf592e881e9 it works just fine.

[boring-cyborg]

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

[nawa]

Reproduced in v1.33.1 and not in v1.33.0

Modules with vendor folder are used, modules-download-mode: vendor in the configuration

[nawa]

Could someone explain what is wrong? Is it golanci-lint or Go tooling behavior, because I noticed that Go is upgraded from 1.15.5->1.15.6 in golangci-lint:v1.33.1

I guess something wrong with golangci-lint because go list -mod=vendor ./... works without errors

[ldez]

FYI the v1.33.1 has been replaced by v1.33.2 (based on v1.33.0) and v1.34.0 (based on master)

[JacobBarba]

Hey guys - we can confirm we are seeing this same error for v1.34.0 as well in our builds. We've been able to resolve for now by pinning to v1.33.2 👍🏻. Output from local lint here:

golangci/golangci-lint info checking GitHub for latest tag
golangci/golangci-lint info found version: 1.34.0 for v1.34.0/linux/amd64
golangci/golangci-lint info installed /go/bin/golangci-lint
level=info msg="[config_reader] Config search paths: [./ /code / /root]"
level=info msg="[config_reader] Used config file .golangci.yml"
level=info msg="[lintersdb] Active 17 linters: [deadcode errcheck gocritic gocyclo golint gosimple govet ineffassign maligned misspell staticcheck structcheck typecheck unconvert unparam unused varcheck]"
level=info msg="[loader] Go packages loading at mode 575 (compiled_files|deps|files|types_sizes|exports_file|imports|name) took 7.036ms"
level=error msg="Running error: context loading failed: failed to load packages: failed to load with go/packages: err: exit status 1: stderr: build flag -mod=readonly only valid when using modules\n"
level=info msg="Memory: 2 samples, avg is 71.6MB, max is 71.6MB"
level=info msg="Execution took 18.4588ms"
make: *** [lint] Error 3

[wtask]

Same here.

go version go1.15.6 windows/amd64
golangci-lint has version 1.34.0 built from 260dc80 on 2020-12-28T16:20:11Z
GO111MODULE=on

Error:

level=error msg="Running error: context loading failed: failed to load packages: failed to load with go/packages: err: exit status 1: stderr: build flag -mod=readonly only valid when using modules

I have this option for .golangci.yml

modules-download-mode: readonly

If remove modules-download-mode from config error is disappeared

[ldez]

The problem is related to a call to go list -mod=readonly -e -f {{context.ReleaseTags}}

https://github.com/golang/tools/blob/929a8494cf60267d89035bc211b797a67b65a6b9/go/packages/golist.go#L848-L852

This was introduced because of go1.16:

golang/tools@2f4fa18

I'm currently trying to find if it's a real bug in golang.org/x/tools or if we need to set up something.

[ldez]

I think that the call creates this problem because of the hard-coded GO111MODULE=off

https://github.com/golang/tools/blob/929a8494cf60267d89035bc211b797a67b65a6b9/internal/gocommand/version.go#L18

$ GO111MODULE=off go list -mod=readonly -e -f {{context.ReleaseTags}}
build flag -mod=readonly only valid when using modules

$ go list -mod=readonly -e -f {{context.ReleaseTags}}
[go1.1 go1.2 go1.3 go1.4 go1.5 go1.6 go1.7 go1.8 go1.9 go1.10 go1.11 go1.12 go1.13 go1.14 go1.15]

[ldez]

I find a fix, I don't really know if it's a hack or just the expected behavior.

To understand, we have to look into the go command:

	case "readonly", "vendor", "mod":
		if !cfg.ModulesEnabled && !base.InGOFLAGS("-mod") {
			base.Fatalf("build flag -mod=%s only valid when using modules", cfg.BuildMod)
		}

https://github.com/golang/go/blob/4fd94558820100129b98f284e21b19fc27a99926/src/cmd/go/internal/work/init.go#L271-L274

Because of the hard-coded GO111MODULE=off the value of cfg.ModulesEnabled is false.

The second clause (!base.InGOFLAGS("-mod") ) checks in the GOFLAGS env var to find a flag that contains -mod.
Currently, in the majority of the cases, the GOFLAGS env var is empty.

So the fix consists of adding the value -mod=%s into the env var GOFLAGS.