ordering of match alternatives matters

[faceprint]

In the example regex (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)(?:r?uary|ch|il|e|y|ust|tember|ober|ember)? +\d{1,2} +\d{4} (which I acknowledge is sloppy since it matches Febtember) having the e alternative before ember causes it not to match November or December as a month. I don't know if this is strictly "correct" behavior, but this works in every other regex engine I've tried.

The workaround of (Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)(?:r?uary|ch|il|ust|tember|ober|ember|e|y)? +\\d{1,2} +\\d{4} does work in CTRE.

regex101 link

godbolt link