some logging

selfprivacy_api/migrations/migrate_to_selfprivacy_channel.py

@@ -5,6 +5,7 @@ from selfprivacy_api.migrations.migration import Migration
 
 
 class MigrateToSelfprivacyChannel(Migration):
+    """Migrate to selfprivacy Nix channel."""
     def get_migration_name(self):
         return "migrate_to_selfprivacy_channel"
 
@@ -13,11 +14,14 @@ class MigrateToSelfprivacyChannel(Migration):
 
     def is_migration_needed(self):
         try:
+            print("Checking if migration is needed")
             output = subprocess.check_output(
                 ["nix-channel", "--list"], start_new_session=True
             )
             output = output.decode("utf-8")
+            print(output)
             first_line = output.split("\n", maxsplit=1)[0]
+            print(first_line)
             return first_line.startswith("nixos") and (
                 first_line.endswith("nixos-21.11") or first_line.endswith("nixos-21.05")
             )
@@ -30,6 +34,7 @@ class MigrateToSelfprivacyChannel(Migration):
         # Also, go to /etc/nixos directory and make a git pull
         current_working_directory = os.getcwd()
         try:
+            print("Changing channel")
             os.chdir("/etc/nixos")
             subprocess.check_output(
                 [