regression bug造句

The developers apologize for a regression bug with the deployment on 6 March 2014, which caused the incorrect removal of | upright size definitions on a handful of pages on the English Wikipedia, among others.
The characters come in fine in Safari, but the actual insertion functionality into the text area doesn't seem to work, ( because of a regression bug affected both Safari 1.3 and 2.0 ).
It's difficult to find regression bug in a sentence. 用regression bug造句挺难的