diff -urNp -x '*.orig' calibre-4.20.0.org/setup/install.py calibre-4.20.0/setup/install.py
--- calibre-4.20.0.org/setup/install.py	2021-06-23 14:08:55.902867594 +0200
+++ calibre-4.20.0/setup/install.py	2021-06-23 14:08:57.906270435 +0200
@@ -142,7 +142,6 @@ class Develop(Command):
         self.consolidate_paths()
         self.install_files()
         self.write_templates()
-        self.install_env_module()
         self.run_postinstall()
         self.success()