On Wed, 2 Nov 2016, Peter Maydell wrote: > On 2 November 2016 at 17:34, Stefano Stabellini <sstabell...@kernel.org> > wrote: > > On Wed, 2 Nov 2016, Thomas Huth wrote: > >> Olaf Hering reported a build failure due to an undefined reference > >> to 'qemu_log_vprintf'. Explicitely including qemu/log.h seems to > >> fix the issue. > >> > >> Signed-off-by: Thomas Huth <th...@redhat.com> > > > > The fix makes sense: > > > > Acked-by: Stefano Stabellini <sstabell...@kernel.org> > > > > However I was unable to reproduce the build failure, so I would like a > > confirmation from Olaf that the fix is working. > > If you configure with the (default) simple trace > backend then trace.h will pull in qemu/log.h > (and in this case trace.h comes in via xen_common.h). > But if you're using a different backend then it won't > bring in that header, and you'll get the build failure. > > This is a fairly common "breaks but only with > some trace backends" compile failure, but I'm > not sure how best to try to make it more robust > (or at least into a 'fails-everywhere' bug).
Personally what I can do is adding --enable-trace-backends=syslog to my test scripts. That is enough to repro the issue. Thanks for the explanation.
