In the past, I have rewritten several scipy functions so I can call them from Numba. This is becoming easier with each Numba release due to the growing support for numpy and python functions.

But I am still facing a bottleneck when deep inside the scipy function a function written in fortran is called. In particular, I am trying to rewrite scipy.optimize.root which calls _root_hybr which calls `minpack._hybrd`

.

The signature of `minpack._hybrd`

is available as it is a compiled function? Is there an automatic way to use it from a numba `njitted`

function? If not, how can I do it manually?