added PermissionError

Author: jfennick

cwltool/job.py

@@ -100,7 +100,10 @@ def relink_initialworkdir(
                     pass
             elif os.path.isdir(host_outdir_tgt) and not vol.resolved.startswith("_:"):
                 ensure_writable(host_outdir_tgt, include_root=True)
-                shutil.rmtree(host_outdir_tgt)
+                try:
+                    shutil.rmtree(host_outdir_tgt)
+                except PermissionError:
+                    pass
             if not vol.resolved.startswith("_:"):
                 try:
                     os.symlink(vol.resolved, host_outdir_tgt)