On Montag, 3. Oktober 2022 12:48:35 CEST Christian Schoenebeck wrote:
> On Montag, 3. Oktober 2022 10:05:14 CEST Daniel P. Berrangé wrote:
> > On Mon, Oct 03, 2022 at 11:05:34AM +0400, marcandre.lur...@redhat.com wrote:
> > > From: Marc-André Lureau <marcandre.lur...@redhat.com>
> > >
> > > This is an alternative configure-time solution to "[PATCH] net:
> > > print a more actionable error when slirp is not found".
> > >
> > > See also "If your networking is failing after updating to the latest git
> > > version of QEMU..." ML thread.
> > >
> > > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> > > ---
> > >
> > > meson.build | 6 ++++++
> > > 1 file changed, 6 insertions(+)
> > >
> > > diff --git a/meson.build b/meson.build
> > > index 8dc661363f..565096001d 100644
> > > --- a/meson.build
> > > +++ b/meson.build
> > > @@ -657,6 +657,12 @@ if not get_option('slirp').auto() or have_system
> > >
> > > endif
> > >
> > > endif
> > >
> > > +if not get_option('slirp').disabled() and not slirp.found()
> > > + error('libslirp is not explicitely disabled and was not found. ' +
> > > + 'Since qemu 7.2, libslirp is no longer included as a submodule
> > > '
> > > +
> > > + 'fallback, you must install it on your system or
> > > --disable-libslirp.') +endif
> >
> > I understand the motivation, but this goes against the main principal
> > of our build time detection, which is to "do the right thing"
> > automatically. If libslirp is not present on the host, then I would
> > consider the need to pass --disable-libslirp to be a bug.
> >
> > I think this pain that people see of loosing slirp support is going to be
> > a pretty short term problem. IMHO it suffices to print a warning message
> > right at the very end of configure, after everything else, just for one
> > or two releases.
>
> I guess that many users would find it a bug as well if this core feature
> just stops working. Even if you add a warning; what will probably happen is
> that packages are first built without. You want to risk that backlash,
> users filing reports, etc?
>
> What about using this error for couple releases and then restoring symmetry?
>
> Independent of this particular patch here, there is probably still something
> wrong with slirp detection.
>
> - in the first run it detected correctly that slirp was not installed
> - then I installed slirp and it detected correctly that it was installed
> - then I uninstalled slirp-dev and slirp and build system still said:
>
> slirp support : YES 4.4.0
>
> ... causing ...
>
> ../net/slirp.c:41:10: fatal error: libslirp.h: No such file or directory
> 41 | #include <libslirp.h>
Oh, it's because Meson caches this build dependency result. From
build/meson-logs/meson-log.txt:
Dependency slirp found: YES 4.4.0 (cached)
https://github.com/mesonbuild/meson/issues/2643
:/
Best regards,
Christian Schoenebeck
