Resolve Windows rooted search paths with Go

internal/engine/discovery.go

@@ -370,7 +370,9 @@ func (iterator *searchCandidateIterator) absoluteCandidate(path string) (string,
 	if filepath.IsAbs(path) {
 		return filepath.Clean(path), nil
 	}
-	if filepath.VolumeName(path) != "" {
+	// Drive-relative and drive-root-relative Windows paths need native
+	// resolution; joining a rooted path to the whole working directory changes it.
+	if filepath.VolumeName(path) != "" || runtime.GOOS == "windows" && len(path) > 0 && os.IsPathSeparator(path[0]) {
 		return filepath.Abs(path)
 	}
 	working, err := iterator.helpers.workingDir()