cmd/go: misleading warning on GOROOT == GOPATH in module mode

[mitar]

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

go version go1.17 linux/amd64

Does this issue reproduce with the latest release?

Yes.

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

go env Output

GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/root/.cache/go-build"
GOENV="/root/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/usr/local/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/usr/local/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="go1.17"
GCCGO="gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/dev/null"
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-build561180864=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I was installing go install github.com/golang/protobuf/[email protected].

Inside a fresh system I did:

$ curl -L https://golang.org/dl/go1.17.linux-amd64.tar.gz | tar -C /usr/local -xz
$ export GOPATH=/usr/local/go
$ export PATH="${GOPATH}/bin:${PATH}"
$ go install github.com/golang/protobuf/[email protected]
warning: GOPATH set to GOROOT (/usr/local/go) has no effect
go: downloading github.com/golang/protobuf v1.5.2
go: downloading google.golang.org/protobuf v1.26.0
$ ls -al /usr/local/go/bin
total 25120
drwxr-xr-x  2 root root     4096 Aug 22 14:11 .
drwxr-xr-x 10 root root     4096 Aug 16 16:27 ..
-rwxr-xr-x  1 root root 14007666 Aug 16 16:30 go
-rwxr-xr-x  1 root root  3318877 Aug 16 16:30 gofmt
-rwxr-xr-x  1 root root  8384142 Aug 22 14:11 protoc-gen-go
$ ls -al /root/go/bin
ls: cannot access '/root/go/bin': No such file or directory

In another fresh system I did:

$ curl -L https://golang.org/dl/go1.17.linux-amd64.tar.gz | tar -C /usr/local -xz
$ export PATH="/usr/local/go/bin:${PATH}"
$ go install github.com/golang/protobuf/[email protected]
go: downloading github.com/golang/protobuf v1.5.2
go: downloading google.golang.org/protobuf v1.26.0
$ ls -al /usr/local/go/bin
total 16932
drwxr-xr-x  2 root root     4096 Aug 16 16:30 .
drwxr-xr-x 10 root root     4096 Aug 16 16:27 ..
-rwxr-xr-x  1 root root 14007666 Aug 16 16:30 go
-rwxr-xr-x  1 root root  3318877 Aug 16 16:30 gofmt
$ ls -al /root/go/bin
total 8196
drwxr-xr-x 2 root root    4096 Aug 22 14:14 .
drwxr-xr-x 4 root root    4096 Aug 22 14:14 ..
-rwxr-xr-x 1 root root 8383846 Aug 22 14:14 protoc-gen-go

What did you expect to see?

As you see, setting GOPATH is critical for getting binary installation into /usr/local/go/bin instead of /root/go/bin. Without it, it does not work. So the warning saying GOPATH set to GOROOT (/usr/local/go) has no effect is misleading. Setting GOPATH has a pretty dramatic effect.

What did you see instead?

I have seen the warning saying GOPATH set to GOROOT (/usr/local/go) has no effect and I assumed I can just remove setting GOPATH but it turns out that is not true. It has an effect.

I think this is important because installation instructions only talk about setting export PATH=$PATH:/usr/local/go/bin, but without setting GOPATH. So installed binaries go into /root/go/bin which is not in PATH based on the installation instructions.

[seankhliao]

Setting GOPATH to GOROOT isn't a supported way of working as it mixes user code with the standard library. If you need to control where the binaries are installed, use GOBIN.

[mitar]

I think issues reported here still hold:

• Warning is misleading.
• Documentation sets PATH only to /usr/local/go/bin but not also sets GOBIN, making go install install into a directory not on PATH.

[seankhliao]

Looks like none of the commands in module mode check check this
cc @bcmills @jayconrod @matloob

[jayconrod]

We should fix this. The install directory should not be set to $GOPATH/bin if the first element of GOPATH is the same as GOROOT.

We should also mention adding $GOPATH/bin to the install instructions. That's covered by #44930.

I'd recommend against installing anything in $GOROOT/bin that isn't usually there. If you're setting GOBIN, it's fine to point it to a directory already in PATH like /usr/local/bin.

[seankhliao]

Can GOROOT == GOPATH be an error instead of just a warning?

[roulpriya]

export GOROOT=/usr/local/go
export PATH=$PATH:$GOROOT/bin
export GOPATH=/home/priyambada/golib
export PATH=$PATH:$GOPATH/bin

This eventually works for me without an error
If you installed GoLang in a custom directory other than the default (/usr/local/), you must specify that directory as the value of the GOROOT variable.

[ianlancetaylor]

@bcmills This is in the 1.18 milestone; time to move to 1.19? Thanks.

[danishprakash]

Is this something an external contributor can pick up? I'd like to work on this. Thanks

[mitar]

@danishprakash Of course.

[Marityr]

export GOROOT=/usr/local/go export PATH=$PATH:$GOROOT/bin export GOPATH=/home/priyambada/golib export PATH=$PATH:$GOPATH/bin

This eventually works for me without an error If you installed GoLang in a custom directory other than the default (/usr/local/), you must specify that directory as the value of the GOROOT variable.

Thank you. when upgrading from 1.19 to 1.20 it helped

[iwdgo]

#70093 was closed with the last update on the message which refers now to the wiki page. Other issues debating on the same topic are now closed. A few can be found above. It seems that issue can now be closed.