Handle missing Compose projects.

images/docker/compose-health-check

@@ -49,6 +49,8 @@ def wait_for_project_health(project, timeout):
     docker_client.ping()
     while True:
         healths = get_project_containers_health(docker_client, project)
+        if not healths:
+            raise RuntimeError(f"No containers found for project {project}.")
         # pylint: disable=no-else-return
         if not get_unhealthy_project_containers(docker_client, project):
             return []
@@ -107,7 +109,10 @@ def main():
             "Compose project wasn't specified, the COMPOSE_PROJECT_NAME variable is missing from the environment and from the .env file."  # noqa: E501
         )
 
+    try:
         unhealthy = wait_for_project_health(project, args.timeout)
+    except Exception as e:  # pylint: disable=broad-except
+        arg_parser.error(str(e))
 
     if not unhealthy:
         print(f"Project {project} is healthy.")