Get it building in a rootless container

bypy/linux/__main__.py

@@ -201,9 +201,9 @@ def create_tarfile(env, compression_level='9'):
     try:
         shutil.rmtree(base)
     except OSError as err:
-        if err.errno != errno.ENOENT:
+        if err.errno not in (errno.ENOENT, errno.EBUSY):  # EBUSY when the directory is mountpoint
             raise
-    os.mkdir(base)
+    os.makedirs(base, exist_ok=True)
     dist = os.path.join(base, f'{kitty_constants["appname"]}-{kitty_constants["version"]}-{arch}.tar')
     with tarfile.open(dist, mode='w', format=tarfile.PAX_FORMAT) as tf:
         cwd = os.getcwd()

kitty_tests/__init__.py

@@ -306,6 +306,7 @@ def __init__(
         if argv is None:
             from kitty.child import openpty
             self.master_fd, self.slave_fd = openpty()
+            self.child_pid = 0
         else:
             self.child_pid, self.master_fd = fork()
             self.is_child = self.child_pid == CHILD