diff --git a/base/utils/fs.go b/base/utils/fs.go
--- a/base/utils/fs.go
+++ b/base/utils/fs.go
@@ -26,0 +27,7 @@ func EnsureDirectory(path string, perm FSPermission) error {
+			//
+			// Public read-only directories are valid executable artifact
+			// directories. In particular, --bin-dir is documented to support
+			// read-only paths.
+			if perm == PublicReadExecPermission && f.Mode().Perm() == 0o555 {
+				return nil
+			}