cmd/go: add hint to read 'go help vcs' to GOVCS errors

Fixes #43596

Change-Id: Iff925d077b5de64161e88c9471402bc7e8885fcd
Reviewed-on: https://go-review.googlesource.com/c/go/+/282713
Trust: Jay Conrod <[email protected]>
Run-TryBot: Jay Conrod <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>

Author: Jay Conrod

src/cmd/go/internal/modget/query.go

@@ -281,14 +281,14 @@ func reportError(q *query, err error) {
 	// TODO(bcmills): Use errors.As to unpack these errors instead of parsing
 	// strings with regular expressions.
 
-	patternRE := regexp.MustCompile("(?m)(?:[ \t(\"`]|^)" + regexp.QuoteMeta(q.pattern) + "(?:[ @:)\"`]|$)")
+	patternRE := regexp.MustCompile("(?m)(?:[ \t(\"`]|^)" + regexp.QuoteMeta(q.pattern) + "(?:[ @:;)\"`]|$)")
 	if patternRE.MatchString(errStr) {
 		if q.rawVersion == "" {
 			base.Errorf("go get: %s", errStr)
 			return
 		}
 
-		versionRE := regexp.MustCompile("(?m)(?:[ @(\"`]|^)" + regexp.QuoteMeta(q.version) + "(?:[ :)\"`]|$)")
+		versionRE := regexp.MustCompile("(?m)(?:[ @(\"`]|^)" + regexp.QuoteMeta(q.version) + "(?:[ :;)\"`]|$)")
 		if versionRE.MatchString(errStr) {
 			base.Errorf("go get: %s", errStr)
 			return

src/cmd/go/internal/vcs/vcs.go

@@ -729,7 +729,7 @@ func checkGOVCS(vcs *Cmd, root string) error {
 		if private {
 			what = "private"
 		}
-		return fmt.Errorf("GOVCS disallows using %s for %s %s", vcs.Cmd, what, root)
+		return fmt.Errorf("GOVCS disallows using %s for %s %s; see 'go help vcs'", vcs.Cmd, what, root)
 	}
 
 	return nil

src/cmd/go/testdata/script/govcs.txt

@@ -5,40 +5,40 @@ env GOPROXY=direct
 # GOVCS stops go get
 env GOVCS='*:none'
 ! go get github.com/google/go-cmp
-stderr 'go get: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^go get: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 env GOPRIVATE='github.com/google'
 ! go get github.com/google/go-cmp
-stderr 'go get: GOVCS disallows using git for private github.com/google/go-cmp'
+stderr '^go get: GOVCS disallows using git for private github.com/google/go-cmp; see ''go help vcs''$'
 
 # public pattern works
 env GOPRIVATE='github.com/google'
 env GOVCS='public:all,private:none'
 ! go get github.com/google/go-cmp
-stderr 'go get: GOVCS disallows using git for private github.com/google/go-cmp'
+stderr '^go get: GOVCS disallows using git for private github.com/google/go-cmp; see ''go help vcs''$'
 
 # private pattern works
 env GOPRIVATE='hubgit.com/google'
 env GOVCS='private:all,public:none'
 ! go get github.com/google/go-cmp
-stderr 'go get: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^go get: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 
 # other patterns work (for more patterns, see TestGOVCS)
 env GOPRIVATE=
 env GOVCS='github.com:svn|hg'
 ! go get github.com/google/go-cmp
-stderr 'go get: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^go get: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 env GOVCS='github.com/google/go-cmp/inner:git,github.com:svn|hg'
 ! go get github.com/google/go-cmp
-stderr 'go get: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^go get: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 
 # bad patterns are reported (for more bad patterns, see TestGOVCSErrors)
 env GOVCS='git'
 ! go get github.com/google/go-cmp
-stderr 'go get github.com/google/go-cmp: malformed entry in GOVCS \(missing colon\): "git"'
+stderr '^go get github.com/google/go-cmp: malformed entry in GOVCS \(missing colon\): "git"$'
 
 env GOVCS=github.com:hg,github.com:git
 ! go get github.com/google/go-cmp
-stderr 'go get github.com/google/go-cmp: unreachable pattern in GOVCS: "github.com:git" after "github.com:hg"'
+stderr '^go get github.com/google/go-cmp: unreachable pattern in GOVCS: "github.com:git" after "github.com:hg"$'
 
 # bad GOVCS patterns do not stop commands that do not need to check VCS
 go list
@@ -50,19 +50,19 @@ env GOPROXY=direct
 env GOPRIVATE=
 env GOVCS=
 ! go get rsc.io/nonexist.svn/hello
-stderr 'go get rsc.io/nonexist.svn/hello: GOVCS disallows using svn for public rsc.io/nonexist.svn'
+stderr '^go get rsc.io/nonexist.svn/hello: GOVCS disallows using svn for public rsc.io/nonexist.svn; see ''go help vcs''$'
 
 # fossil is disallowed by default
 env GOPRIVATE=
 env GOVCS=
 ! go get rsc.io/nonexist.fossil/hello
-stderr 'go get rsc.io/nonexist.fossil/hello: GOVCS disallows using fossil for public rsc.io/nonexist.fossil'
+stderr '^go get rsc.io/nonexist.fossil/hello: GOVCS disallows using fossil for public rsc.io/nonexist.fossil; see ''go help vcs''$'
 
 # bzr is disallowed by default
 env GOPRIVATE=
 env GOVCS=
 ! go get rsc.io/nonexist.bzr/hello
-stderr 'go get rsc.io/nonexist.bzr/hello: GOVCS disallows using bzr for public rsc.io/nonexist.bzr'
+stderr '^go get rsc.io/nonexist.bzr/hello: GOVCS disallows using bzr for public rsc.io/nonexist.bzr; see ''go help vcs''$'
 
 # git is OK by default
 env GOVCS=
@@ -77,12 +77,12 @@ env GONOSUMDB='*'
 # git can be disallowed
 env GOVCS=public:hg
 ! go get rsc.io/nonexist.git/hello
-stderr 'go get rsc.io/nonexist.git/hello: GOVCS disallows using git for public rsc.io/nonexist.git'
+stderr '^go get rsc.io/nonexist.git/hello: GOVCS disallows using git for public rsc.io/nonexist.git; see ''go help vcs''$'
 
 # hg can be disallowed
 env GOVCS=public:git
 ! go get rsc.io/nonexist.hg/hello
-stderr 'go get rsc.io/nonexist.hg/hello: GOVCS disallows using hg for public rsc.io/nonexist.hg'
+stderr '^go get rsc.io/nonexist.hg/hello: GOVCS disallows using hg for public rsc.io/nonexist.hg; see ''go help vcs''$'
 
 # Repeat in GOPATH mode. Error texts slightly different.
 
@@ -91,40 +91,40 @@ env GO111MODULE=off
 # GOVCS stops go get
 env GOVCS='*:none'
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 env GOPRIVATE='github.com/google'
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: GOVCS disallows using git for private github.com/google/go-cmp'
+stderr '^package github.com/google/go-cmp: GOVCS disallows using git for private github.com/google/go-cmp; see ''go help vcs''$'
 
 # public pattern works
 env GOPRIVATE='github.com/google'
 env GOVCS='public:all,private:none'
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: GOVCS disallows using git for private github.com/google/go-cmp'
+stderr '^package github.com/google/go-cmp: GOVCS disallows using git for private github.com/google/go-cmp; see ''go help vcs''$'
 
 # private pattern works
 env GOPRIVATE='hubgit.com/google'
 env GOVCS='private:all,public:none'
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 
 # other patterns work (for more patterns, see TestGOVCS)
 env GOPRIVATE=
 env GOVCS='github.com:svn|hg'
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 env GOVCS='github.com/google/go-cmp/inner:git,github.com:svn|hg'
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp'
+stderr '^package github.com/google/go-cmp: GOVCS disallows using git for public github.com/google/go-cmp; see ''go help vcs''$'
 
 # bad patterns are reported (for more bad patterns, see TestGOVCSErrors)
 env GOVCS='git'
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: malformed entry in GOVCS \(missing colon\): "git"'
+stderr '^package github.com/google/go-cmp: malformed entry in GOVCS \(missing colon\): "git"$'
 
 env GOVCS=github.com:hg,github.com:git
 ! go get github.com/google/go-cmp
-stderr 'package github.com/google/go-cmp: unreachable pattern in GOVCS: "github.com:git" after "github.com:hg"'
+stderr '^package github.com/google/go-cmp: unreachable pattern in GOVCS: "github.com:git" after "github.com:hg"$'
 
 # bad GOVCS patterns do not stop commands that do not need to check VCS
 go list
@@ -133,19 +133,19 @@ go list
 env GOPRIVATE=
 env GOVCS=
 ! go get rsc.io/nonexist.svn/hello
-stderr 'package rsc.io/nonexist.svn/hello: GOVCS disallows using svn for public rsc.io/nonexist.svn'
+stderr '^package rsc.io/nonexist.svn/hello: GOVCS disallows using svn for public rsc.io/nonexist.svn; see ''go help vcs''$'
 
 # fossil is disallowed by default
 env GOPRIVATE=
 env GOVCS=
 ! go get rsc.io/nonexist.fossil/hello
-stderr 'package rsc.io/nonexist.fossil/hello: GOVCS disallows using fossil for public rsc.io/nonexist.fossil'
+stderr '^package rsc.io/nonexist.fossil/hello: GOVCS disallows using fossil for public rsc.io/nonexist.fossil; see ''go help vcs''$'
 
 # bzr is disallowed by default
 env GOPRIVATE=
 env GOVCS=
 ! go get rsc.io/nonexist.bzr/hello
-stderr 'package rsc.io/nonexist.bzr/hello: GOVCS disallows using bzr for public rsc.io/nonexist.bzr'
+stderr '^package rsc.io/nonexist.bzr/hello: GOVCS disallows using bzr for public rsc.io/nonexist.bzr; see ''go help vcs''$'
 
 # git is OK by default
 env GOVCS=
@@ -160,12 +160,12 @@ env GONOSUMDB='*'
 # git can be disallowed
 env GOVCS=public:hg
 ! go get rsc.io/nonexist.git/hello
-stderr 'package rsc.io/nonexist.git/hello: GOVCS disallows using git for public rsc.io/nonexist.git'
+stderr '^package rsc.io/nonexist.git/hello: GOVCS disallows using git for public rsc.io/nonexist.git; see ''go help vcs''$'
 
 # hg can be disallowed
 env GOVCS=public:git
 ! go get rsc.io/nonexist.hg/hello
-stderr 'package rsc.io/nonexist.hg/hello: GOVCS disallows using hg for public rsc.io/nonexist.hg'
+stderr '^package rsc.io/nonexist.hg/hello: GOVCS disallows using hg for public rsc.io/nonexist.hg; see ''go help vcs''$'
 
 -- go.mod --
 module m