Hi,
In most cases ( * ) is formatted with spaces (that's necessary because otherwise it clashes with comment syntax).
But here's a case where it's not:
let op = if b then ( * ) else ( + ) in ()
It gets formatted as if true then (*) else (+), which crashes ocamlformat.
This seems to be related to the ~parens:false param.
This also happens in the following contrived example (which might indicate a larger problem):