Learned that I should not refer to env vars directly so I removed all references.

app/Helpers/Attachments/AttachmentHelper.php

@@ -65,7 +65,7 @@ class AttachmentHelper implements AttachmentHelperInterface
         $this->attachments   = new Collection;
         $this->uploadDisk    = Storage::disk('upload');
 
-        if ('testing' === env('APP_ENV')) {
+        if ('testing' === config('app.env')) {
             Log::warning(sprintf('%s should not be instantiated in the TEST environment!', \get_class($this)));
         }
     }