* On Mac, do not use Posix Ucontextes with gcc v4.[1-5] since this
leads to a strange error, with user code segfaulting sometimes when
the generated code is not perfectly aligned (which is not
* On Mac, do not use Posix Ucontextes with gcc v4.[1-5] since this
leads to a strange error, with user code segfaulting sometimes when
the generated code is not perfectly aligned (which is not