cmd/go: `go doc -http` ignores module when running from GOPATH

[dolmen]

Go version

go version go1.25.3 darwin/arm64

Output of go env in your module/workspace:

GO111MODULE=''
GOMOD='/Users/dolmen/go/src/github.com/go-chi/chi/toto/go.mod'
GOMODCACHE='/Users/dolmen/go/pkg/mod'
GOPATH='/Users/dolmen/go'

What did you do?

$ go version
go version go1.25.3 darwin/arm64
$ mkdir -p $(go env GOPATH)/src/github.com/go-chi
$ cd $(go env GOPATH)/src/github.com/go-chi
$ LANG=C git clone https://github.com/go-chi/chi.git
Cloning into 'chi'...
remote: Enumerating objects: 3823, done.
remote: Counting objects: 100% (1044/1044), done.
remote: Compressing objects: 100% (346/346), done.
remote: Total 3823 (delta 864), reused 701 (delta 697), pack-reused 2779 (from 4)
Receiving objects: 100% (3823/3823), 3.82 MiB | 14.85 MiB/s, done.
Resolving deltas: 100% (2372/2372), done.
$ cd chi
$ pwd
/Users/dolmen/go/src/github.com/go-chi/chi
$ go list
github.com/go-chi/chi/v5
$ # Note that path in $GOPATH/src doesn't match the module path
$ # github.com/go-chi/chi vs github.com/go-chi/chi/v5
$ go env GO111MODULE

$ go doc | head -1
package chi // import "github.com/go-chi/chi/v5"
$ GO111MODULE=off go doc | head -1
package chi // import "github.com/go-chi/chi"
$ # So far this is fine: doc on stdout respects GO111MODULE
$ go doc -http .
doc: Documentation server listening on addr http://localhost:54952

What did you see happen?

Web browser opens with http://localhost:54952/github.com/go-chi/chi (path matches the path below $GOPATH/src like if GO111MODULE=off)

The same incorrect behaviour happens with go doc -http $(go list) (an explicit package path derived from the Go module) like it happens with . (relative path).

go doc -http should respect GO111MODULE setting (which defaults to on since Go 1.16) to be consistent with go doc.

What did you expect to see?

Web browser opens with Web browser opens with http://localhost:54952/github.com/go-chi/chi/v5 (package path matches go list which is built from the Go module).

Note that go doc -http (without an explicit package path)

[gabyhelp]

Related Issues

• cmd/go: module mode removes concept of global docs #33710 (closed)
• cmd/doc: 'go doc $pkg' prefers GOPATH instead of active module #28992 (closed)
• cmd/go/doc: behaviour of "go doc" in module mode is not documented #61032
• go/build: resolve package in GOPATH when GO111MODULE=on outside module #34669 (closed)
• cmd/go: doc confused by $GOPATH/src/mod #26635 (closed)
• godoc does not work for local modules #45083 (closed)
• go/doc: doc doesn't work in module mode #27239 (closed)
• cmd/doc: go doc rsc.io/quote/v3 in module mode shows wrong import path #30778 (closed)
• cmd/doc: `go doc <Symbol>` shows "." as package import path #60645
• cmd/doc: -http fails on Windows with invalid port #74137 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[dolmen]

Thanks @gabyhelp for reminding me about a related ticket that I have opened 2 years ago: #61032

[dolmen]

Thanks @gabyhelp for linking to "go doc" bugs (long before the -http times) which are hinting to the kind of issue, very helpful as they got fixed:

• cmd/doc: 'go doc $pkg' prefers GOPATH instead of active module #28992: fixed by CL 183991
• go/doc: doc doesn't work in module mode #27239: probably a duplicate of 28992

[dr2chase]

@golang/command-line