Profiling of Cython cdef functions is enabled permanently
setup.py enables Cython's "linetrace" directive. This does not yet enable line tracing (doing so requires defining the C macro
CYTHON_TRACE), but it has the unwelcome effect of permanently enabling Cython's support for profiling. At least in some cases (for example automatic magnetic gauge computations) this seriously degrades performance.
This issue was introduced by 10faf93a. Any fix should preserve the ability to enable line tracing (and profiling) through the
See also the related mailing list discussion.