I'm not sure if I'm misunderstanding the documentation, but I would expect the following lines to print the same result.

test:
    echo {{ replace_regex('ping-pong', '-.*$', '') }}
    echo {{ trim_end_match('ping-pong', '-.*$') }}

In fact, the first line prints ping as expected, but the second line prints ping-pong. Isn't trim_end_match supposed to take a regular expression?