[Diff][Fixed] Problems when using an output and no variant specified

CHANGELOG.md

@@ -30,6 +30,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - PCB Print:
   - Interference between the visible layers in the PRL file and the results
     when scaling. (#407)
+- Diff:
+  - Problems when using an output and no variant specified.
 
 
 ## [1.6.1] - 2023-03-16

kibot/out_diff.py

@@ -390,7 +390,11 @@ class DiffOptions(BaseOptions):
         if not out._done:
             run_output(out)
         res = self.cache_file(fname)
-        self.git_hash = out.options.variant.file_id if self.use_file_id else out.options.variant.name+'_variant'
+        variant = out.options.variant
+        if variant is None:
+            self.git_hash = 'no_variant'
+        else:
+            self.git_hash = variant.file_id if self.use_file_id else variant.name+'_variant'
         return res
 
     def cache_current(self):