1 files changed, 19 insertions, 3 deletions
diff --git a/vendor/golang.org/x/tools/go/packages/external.go b/vendor/golang.org/x/tools/go/packages/external.go
index 4335c1eb1..c2b4b711b 100644
--- a/vendor/golang.org/x/tools/go/packages/external.go
+++ b/vendor/golang.org/x/tools/go/packages/external.go
@@ -34,8 +34,8 @@ type DriverRequest struct {
 	// Tests specifies whether the patterns should also return test packages.
 	Tests bool `json:"tests"`
 
-	// Overlay maps file paths (relative to the driver's working directory) to the byte contents
-	// of overlay files.
+	// Overlay maps file paths (relative to the driver's working directory)
+	// to the contents of overlay files (see Config.Overlay).
 	Overlay map[string][]byte `json:"overlay"`
 }
 
@@ -119,7 +119,19 @@ func findExternalDriver(cfg *Config) driver {
 		stderr := new(bytes.Buffer)
 		cmd := exec.CommandContext(cfg.Context, tool, words...)
 		cmd.Dir = cfg.Dir
-		cmd.Env = cfg.Env
+		// The cwd gets resolved to the real path. On Darwin, where
+		// /tmp is a symlink, this breaks anything that expects the
+		// working directory to keep the original path, including the
+		// go command when dealing with modules.
+		//
+		// os.Getwd stdlib has a special feature where if the
+		// cwd and the PWD are the same node then it trusts
+		// the PWD, so by setting it in the env for the child
+		// process we fix up all the paths returned by the go
+		// command.
+		//
+		// (See similar trick in Invocation.run in ../../internal/gocommand/invoke.go)
+		cmd.Env = append(slicesClip(cfg.Env), "PWD="+cfg.Dir)
 		cmd.Stdin = bytes.NewReader(req)
 		cmd.Stdout = buf
 		cmd.Stderr = stderr
@@ -138,3 +150,7 @@ func findExternalDriver(cfg *Config) driver {
 		return &response, nil
 	}
 }
+
+// slicesClip removes unused capacity from the slice, returning s[:len(s):len(s)].
+// TODO(adonovan): use go1.21 slices.Clip.
+func slicesClip[S ~[]E, E any](s S) S { return s[:len(s):len(s)] }