Skip attach operation for OS versions that no longer support attach

changelogs/fragments/10253-redhat_subscription-attach.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - redhat_subscription - skip attach operation for OS versions where the attach sub-command has been removed (https://github.com/ansible-collections/community.general/issues/10253)

plugins/modules/redhat_subscription.py

@@ -116,6 +116,7 @@
     description:
       - Upon successful registration, auto-consume available subscriptions.
       - Please note that the alias O(ignore:autosubscribe) was removed in community.general 9.0.0.
+      - Since community.general X.Y.Z, this option does nothing for RHEL 10+ and Fedora 41+ where attach has been removed.
     type: bool
   activationkey:
     description:
@@ -430,6 +431,24 @@ def register(self, was_registered, username, password, token, auto_attach, activ
             Raises:
               * Exception - if any error occurs during the registration
         '''
+
+        def str2int(s, default=0):
+            try:
+                return int(s)
+            except ValueError:
+                return default
+
+        distro_id = distro.id()
+        distro_version_parts = distro.version_parts()
+        distro_version = tuple(str2int(p) for p in distro_version_parts)
+
+        # subscription-manager attach command was removed in Fedora 41 and RHEL 10
+        if (
+            (distro_id == 'rhel' and distro_version[0] >= 10)
+            or (distro_id == 'fedora' and distro_version[0] >= 41)
+        ):
+            auto_attach = False
+
         # There is no support for token-based registration in the D-Bus API
         # of rhsm, so always use the CLI in that case;
         # also, since the specified environments are names, and the D-Bus APIs