SyntaxError: unterminated parenthetical

From using:

VerEx().startOfLine().then("aaa").or("bbb").endOfLine()

I'd expect it to compile to something like:

/^(aaa|bbb)$/

...but since endOfLine discards existing suffixes (where there is a capture group close parenthesis from .or), it leaves the capture group open, resulting in:

/^(aaa|bbb$/