On Tue, 4 Sep 2018 at 13:26, Michael Hudson-Doyle <firstname.lastname@example.org> wrote:
The bug is that when you lie to cffi about the return type of a variable, in particular when you say a function returning a float does not return a float, the x87 stack is not wiped to the extent required by the calling convention. glibc 2.28 rewrote the cos function in a way that apparently now cares about this (or I guess gcc now compiles the function in a way that cares about this) but make no mistake, it only ever worked by chance before. So I think the test_sin_no_return_value test should be skipped on i386. (I'll file an upstream issue I guess).