Dear Maintainer,
upgrading from Debian 12 to Debian 13 broke a number of
docker-compose.yml files. Debugging the problem lead me to the following
upstream issue:

   Environment Variable Default Not Working Correctly v1.3.0
https://github.com/containers/podman-compose/issues/1105

The bug was corrected in this PR:

https://github.com/containers/podman-compose/pull/1110

The actual patch consists in deleting a single line:

##################################################
--- /usr/lib/python3/dist-packages/podman_compose.py
+++ /usr/lib/python3/dist-packages/podman_compose.py
@@ -270,7 +270,6 @@
              svc_envs = {k: v for k, v in value['environment'].items()
if k not in subs_dict}
              # we need to add `svc_envs` to the `subs_dict` so that it
can evaluate the
              # service environment that reference to another service
environment.
-            subs_dict.update(svc_envs)
              svc_envs = rec_subs(svc_envs, subs_dict)
              subs_dict.update(svc_envs)

##################################################

After this change, everything works again.

Regards,

Antonio