From: Quan Tong <quantonganh@gmail.com>
Date: Mon, 6 Nov 2023 01:00:31 +0000 (+0700)
Subject: cmd/go/internal/modload: ignore $GOPATH/go.mod
X-Git-Tag: go1.22rc1~379
X-Git-Url: http://www.git.cypherpunks.ru/?a=commitdiff_plain;h=0891b17ce53de8350689a89e55583794a12d302e;hp=07c388f17c039c0bb9a3fd0fd70bf5494aa7ee2c;p=gostls13.git

cmd/go/internal/modload: ignore $GOPATH/go.mod

The existing implementation returns a fatal error if $GOPATH/go.mod exists.
We couldn't figure out what directory the go tool was treating as $GOPATH
in the error message.

Fixes #46807

Change-Id: If9db4c0377f7c36af9c367398d3da494be04cd41
Reviewed-on: https://go-review.googlesource.com/c/go/+/539596
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
---

diff --git a/src/cmd/go/internal/modload/init.go b/src/cmd/go/internal/modload/init.go
index b9d9d2e552..f4f4a68254 100644
--- a/src/cmd/go/internal/modload/init.go
+++ b/src/cmd/go/internal/modload/init.go
@@ -485,7 +485,13 @@ func Init() {
 	if len(list) > 0 && list[0] != "" {
 		gopath = list[0]
 		if _, err := fsys.Stat(filepath.Join(gopath, "go.mod")); err == nil {
-			base.Fatalf("$GOPATH/go.mod exists but should not")
+			fmt.Fprintf(os.Stderr, "go: warning: ignoring go.mod in $GOPATH %v\n", gopath)
+			if RootMode == NeedRoot {
+				base.Fatal(ErrNoModRoot)
+			}
+			if !mustUseModules {
+				return
+			}
 		}
 	}
 }
diff --git a/src/cmd/go/testdata/script/env_issue46807.txt b/src/cmd/go/testdata/script/env_issue46807.txt
new file mode 100644
index 0000000000..e37bc63e6c
--- /dev/null
+++ b/src/cmd/go/testdata/script/env_issue46807.txt
@@ -0,0 +1,12 @@
+! go mod tidy
+stderr '^go: warning: ignoring go.mod in \$GOPATH'
+stderr '^go: go.mod file not found in current directory or any parent directory; see ''go help modules'''
+
+go env
+stdout 'GOPATH='
+stderr '^go: warning: ignoring go.mod in \$GOPATH'
+
+-- $GOPATH/go.mod --
+module bug
+
+go 1.21
\ No newline at end of file