Ah, that would explain it ...

On Sunday, August 28, 2016, Stefan Dösinger <stefandoesinger@gmail.com> wrote:
On 2016-08-27 14:09, DavidL wrote:
> Huh ... this is embarrassing, although pleasantly so: it just compiled
> and linked - I don't know why, I don't think I made any changes - but it
> works now. I will investigate a little bit further to see if the why is
> interesting and report what I might've done if so ... probably something
> stupid :)
If you edit Makefile.in you have to run make from the top level
directory, not just dlls/winejoystick.drv/ to regenerate Makefile.