Re: clock_settime(2) error for non-settable clocks

On 2020-03-20, Eric Rannaud [off-list ref] wrote:

Should we update the manpage to more fully explain the range of
possible errors or instead try to have more consistent errors? For
syscalls, what's the backward-compatibility contract for errno values?

It's the same as everything else -- "if it breaks an existing
application, it's a regression". There was an infamous case of this
exact scenario happening (changing the errno returned from an ioctl
broke pulseaudio) in 2012[1].

[1]: https://lore.kernel.org/lkml/CA+55aFzX56kPPwSO97X=UyPaMzV5QRNG9ScN=nxnHFjmz=_8yA@mail.gmail.com/ (local)

-- 
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>