On Thu, Dec 13, 2018 at 03:22:10PM +0100, Kevin Wolf wrote: > Am 13.12.2018 um 11:11 hat Daniel P. Berrangé geschrieben: > > On Wed, Dec 12, 2018 at 04:04:10PM -0600, Eric Blake wrote: > > > When a qemu-io command fails, it's best if the failure message > > > goes to stderr rather than stdout. > > > > > > Reported-by: Richard W.M. Jones <rjo...@redhat.com> > > > Signed-off-by: Eric Blake <ebl...@redhat.com> > > > --- > > > > > > RFC because at least iotest 60 (found by -qcow2 -g quick) breaks due > > > to reordering of output lines, and I'd rather know if we like this > > > idea before bothering to revisit all affected iotests (including > > > discovering if other slower ones have similar problems). > > > > I think the change is correct. Error messages should never go to stdout. > > I'm not sure about this, to be honest. qemu-io is first and foremost an > interactive program, and spreading output across two streams, one > buffered and one unbuffered, in an interactive program feels like it has > to result in surprises.
Just for the record we're using qemu-io extensively for testing nbdkit, and it's always used non-interactively (ie. ‘qemu-io -c’). The bug (if it is such) was found because I was using qemu-io to test for expected errors. https://github.com/libguestfs/nbdkit/search?q=qemu-io Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v