Re: [Qemu-devel] [Bug 929638] Re: qemu 1.0 unable to compile on the pandaboard ES

[Paul Brook]

> > On ARM Linux glibc provides a makecontext() that always fails ENOSYS,
> > so our configure test thinks there is makecontext support but when we
> > try to use it for coroutines it will fail and we abort.
> > 
> > I have a workaround in qemu-linaro that just forces the makecontext
> > test to fail on ARM but I don't like that much. It would be better
> > to either drop our requirement for makecontext (Paolo had some patches
> > to try to do this IIRC) or to handle it failing at runtime.
> 
> Or make the configure test be an execution test and always disable it for
> cross-compile?

I'd rather not.  If at all possible we should avoid runtime tests.  Even for 
"native" systems they generally give the wrong answer as the machine you're 
building on often isn't the one you will be running on.  If we know arm hosts 
are broken then that's what we should test for in configure (with a comment 
saying why).

IMO consistency between builds for the same target environment is more 
important than opportunistically probing in a native builds.

Paul