> >
> > But fails using dune:
> >
> > dune build
>
> Found the problem: dune is compiling with -opaque ... but could
> not find yet how to remove this option!

dune build --release ...

A bit annoying still, I will fill an issue on dune's github.

> > gives this error without flambda:
> >
> > File "test.ml", line 12, characters 18-52:
> > 12 | module FloatMat = Mat.Make [@inlined always] (Float)
> >                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > Error (warning 55): Cannot inline: Unknown function
> >
> > and this error with flambda:
> >
> > File "test.ml", line 12, characters 18-52:
> > 12 | module FloatMat = Mat.Make [@inlined always] (Float)
> >                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > Error (warning 55): Cannot inline: [@inlined] attribute was not used on this function application (the optimizer did not know what function was being applied)
> >