Thanks. Does it make sense that changing a function definition from point-free to an explicit definition should eliminate this exception? Because that seems to have been the problem. On Wed, Sep 10, 2014 at 6:20 PM, Jeremy Yallop wrote: > On 10 September 2014 21:32, Yotam Barnoy wrote: > > I just encountered this nasty RUNTIME error in my code. What does it > mean? > > How does it happen? > > The behaviour is documented in the manual: > > http://caml.inria.fr/pub/docs/manual-ocaml-400/manual021.html#toc75 > > See the paragraph beginning "Currently, the compiler requires [...]". >