@njs: to point out that usefulness of this module is not just wishful thinking. I just used it to locate, up to the line in a Python extension module written in C, a bug in Sagemath (that has perhaps 20 FPU-using extensions, some of them as large as numpy).  (Without using it we were pulling out our hair for weeks over this)

https://trac.sagemath.org/ticket/22799#comment:103

Thanks goodness that fpectl@FreeBSD is easy to fix by commenting out a couple of "fpresetsticky(fpgetsticky());" lines---fpresetsticky() is not available on 64-bit platforms.
(our primary concern is OSX, where fpectl never worked---fortunately FreeBSD is close enough relative...)