Re: [libvirt] [Qemu-devel] [PULL 25/26] block: Remove deprecated -drive option serial

On 10.07.2018 17:24, Peter Krempa wrote: > On Tue, Jul 10, 2018 at 17:01:22 +0200, Cornelia Huck wrote: >> On Tue, 10 Jul 2018 16:39:31 +0200 >> Peter Krempa <pkrempa(a)redhat.com&gt; wrote: >>> On Tue, Jul 10, 2018 at 16:22:08 +0200, Cornelia Huck wrote: >>>> On Tue, 10 Jul 2018 07:59:15 +0200 >>>> Markus Armbruster <armbru(a)redhat.com&gt; wrote: > > [...] > >>>> "ERROR: 'old_option' is deprecated and will be removed; use 'modern_option' instead" >>>> >>>> and do an exit(1). >>>> >>>> Would that be workable? >>> >>> For delivering the warnings via monitor you'll need a store that will >>> collect all the warnings and prepare them for delivery. You've got >>> basically two options: >>> >>> 1) monitor command to poll for deprecated options >>> 2) event with deprecated options >>> >>> Both require storing them since libvirt connects to the monitor only >>> after the command line is processed. >>> >>> Warnings printed to stderr are nearly useless because until something >>> breaks nobody bothers to read the log files. >> >> So, from that I gather that a hard failure would be the easiest for >> libvirt to detect (and everything else would become complicated really >> quickly), right? > > People start complaining only when stuff breaks. If anything is optional > people will usually not enable it. That makes any non-mandatory option > not work in most cases. So would it help if we "invert" the logic, i.e. deprecated_report() would do exit(1) by default? Then, if the (human) users still want to continue with the deprecated option, they have to add a "--ignore-deprecation" command line switch to make QEMU start successfully...