diff --git a/src/cmd/go/internal/modfetch/codehost/vcs.go b/src/cmd/go/internal/modfetch/codehost/vcs.go
index 03def8e082..9e862a0ef8 100644
--- a/src/cmd/go/internal/modfetch/codehost/vcs.go
+++ b/src/cmd/go/internal/modfetch/codehost/vcs.go
@@ -22,6 +22,17 @@ import (
 	"cmd/go/internal/str"
 )
 
+// A VCSError indicates an error using a version control system.
+// The implication of a VCSError is that we know definitively where
+// to get the code, but we can't access it due to the error.
+// The caller should report this error instead of continuing to probe
+// other possible module paths.
+type VCSError struct {
+	Err error
+}
+
+func (e *VCSError) Error() string { return e.Err.Error() }
+
 func NewRepo(vcs, remote string) (Repo, error) {
 	type key struct {
 		vcs    string
@@ -33,6 +44,9 @@ func NewRepo(vcs, remote string) (Repo, error) {
 	}
 	c := vcsRepoCache.Do(key{vcs, remote}, func() interface{} {
 		repo, err := newVCSRepo(vcs, remote)
+		if err != nil {
+			err = &VCSError{err}
+		}
 		return cached{repo, err}
 	}).(cached)
 
diff --git a/src/cmd/go/internal/modfetch/repo.go b/src/cmd/go/internal/modfetch/repo.go
index 003479461c..c8b133574e 100644
--- a/src/cmd/go/internal/modfetch/repo.go
+++ b/src/cmd/go/internal/modfetch/repo.go
@@ -237,6 +237,9 @@ func lookup(path string) (r Repo, err error) {
 func lookupCodeRepo(rr *get.RepoRoot) (codehost.Repo, error) {
 	code, err := codehost.NewRepo(rr.VCS, rr.Repo)
 	if err != nil {
+		if _, ok := err.(*codehost.VCSError); ok {
+			return nil, err
+		}
 		return nil, fmt.Errorf("lookup %s: %v", rr.Root, err)
 	}
 	return code, nil
diff --git a/src/cmd/go/internal/modload/import.go b/src/cmd/go/internal/modload/import.go
index 3b954f18fe..78ae83e4bf 100644
--- a/src/cmd/go/internal/modload/import.go
+++ b/src/cmd/go/internal/modload/import.go
@@ -14,6 +14,7 @@ import (
 	"strings"
 
 	"cmd/go/internal/cfg"
+	"cmd/go/internal/modfetch/codehost"
 	"cmd/go/internal/module"
 	"cmd/go/internal/par"
 	"cmd/go/internal/search"
@@ -133,6 +134,9 @@ func Import(path string) (m module.Version, dir string, err error) {
 
 	m, _, err = QueryPackage(path, "latest", Allowed)
 	if err != nil {
+		if _, ok := err.(*codehost.VCSError); ok {
+			return module.Version{}, "", err
+		}
 		return module.Version{}, "", &ImportMissingError{ImportPath: path}
 	}
 	return m, "", &ImportMissingError{ImportPath: path, Module: m}
diff --git a/src/cmd/go/internal/modload/query.go b/src/cmd/go/internal/modload/query.go
index bd3141865c..3b550f1db7 100644
--- a/src/cmd/go/internal/modload/query.go
+++ b/src/cmd/go/internal/modload/query.go
@@ -6,6 +6,7 @@ package modload
 
 import (
 	"cmd/go/internal/modfetch"
+	"cmd/go/internal/modfetch/codehost"
 	"cmd/go/internal/module"
 	"cmd/go/internal/semver"
 	"fmt"
@@ -223,6 +224,11 @@ func QueryPackage(path, query string, allowed func(module.Version) bool) (module
 	for p := path; p != "."; p = pathpkg.Dir(p) {
 		info, err := Query(p, query, allowed)
 		if err != nil {
+			if _, ok := err.(*codehost.VCSError); ok {
+				// A VCSError means we know where to find the code,
+				// we just can't. Abort search.
+				return module.Version{}, nil, err
+			}
 			if finalErr == errMissing {
 				finalErr = err
 			}
diff --git a/src/cmd/go/testdata/script/mod_vcs_missing.txt b/src/cmd/go/testdata/script/mod_vcs_missing.txt
new file mode 100644
index 0000000000..fb146b4415
--- /dev/null
+++ b/src/cmd/go/testdata/script/mod_vcs_missing.txt
@@ -0,0 +1,11 @@
+[exec:bzr] skip 'tests NOT having bzr'
+[!net] skip
+
+env GO111MODULE=on
+env GOPROXY=
+
+! go list launchpad.net/gocheck
+stderr '"bzr": executable file not found'
+
+-- go.mod --
+module m