x/tools/cmd/stringer: internal error when importing go packages on go1.18 for Linux

[avislash]

What version of Go are you using (go version)?

$ go version
go version go1.18 linux/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

Ubuntu 20.04 LTS (Linux ubhold 5.11.0-46-generic #51~20.04.1-Ubuntu SMP Fri Jan 7 06:51:40 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux)

NOTE: This works as expected on Mac OS. This only appears to be a problem on Linux and this was working fine before with go1.17.

go env Output

$ go env
GO111MODULE="on"
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/redacted/.cache/go-build"
GOENV="/home/redacted/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/redacted/go/pkg/mod"
GONOPROXY="github.com/redacted*"
GONOSUMDB="github.com/redacted/*"
GOOS="linux"
GOPATH="/home/redacted/go"
GOPRIVATE="github.com/redacted/*"
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/lib/go-1.18"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go-1.18/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.18"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="/usr/bin/g++-7"
CGO_ENABLED="1"
GOMOD="/home/redacted/go_tutorial/stringer_is_broke_af/go.mod"
GOWORK=""
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 -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build4289626171=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I tried to use stringer to auto-generate the Stringer interface for an enum using go1.18 (installed via APT) on Ubuntu 20.04 LTS.

Using go generate or just running stringer on the code below reproduces the error for me

//go:generate stringer -type=Foo -trimprefix Foo
package main

import "fmt"
type Foo uint64
const (
    FooZero Foo = iota
    FooOne
    FooTwo
)

func main() {
    var f Foo
    fmt.Println(f)
}

If I remove the "fmt" import and instead just use a print() I get no errors.

//go:generate stringer -type=Foo -trimprefix Foo
package main

type Foo uint64
const (
    FooZero Foo = iota
    FooOne
    FooTwo
)

func main() {
    var f Foo
    print(f)
}

What did you expect to see?

I expected to see a file called foo_string.go that implements a String() method for the Foo enum

What did you see instead?

$ go generate .
stringer: internal error: package "fmt" without types was imported from "stringer_is_broke_af"
main.go:1: running "stringer": exit status 1

[seankhliao]

what version of stringer?

[mknyszek]

Is this issue new in Go 1.18?

[mknyszek]

CC @golang/tools-team

[avislash]

Thanks for the prompt response! I figured out the root issue, it turns out the stringer binary was not being updated when I tried to update to golang.org/x/tools v0.1.10.

I had to blow away stringer in go/bin/ and then reinstall using go install golang.org/x/tools/cmd/stringer@latest.

Once I did this I was able to use go generate again.

I'm still not really sure why this manifested in Linux and not in Mac OS.