Re: If your networking is failing after updating to the latest git version of QEMU...

[Thomas Huth]

On 29/09/2022 04.32, Jason Wang wrote:
> On Thu, Sep 29, 2022 at 1:06 AM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
> > On 28/9/22 10:27, Thomas Huth wrote:
> > > ... it might have happened due to the removal of the "slirp" submodule
> > > from the git repository. For example if you see an error message like this:
> > >
> > >    Parameter 'type' expects a netdev backend type
> > >
> > > this likely means that the "user" mode backend type is not available in
> > > your binary anymore. To fix it, simply install "libslirp-devel" (or
> > > libslirp-dev or however it is called) from your OS distribution and
> > > recompile.
> >
> > Thanks for the hint Thomas. I'm afraid many developers will miss your
> > email.
> >
> > Jason, Marc-André, could we improve the buildsys check or display
> > a more helpful information from the code instead?
>
> It looks to me we need to improve the build.

I'm not sure there is anything to improve in the build system - 
configure/meson.build are just doing what they should: Pick the default 
value for "slirp" if the user did not explicitly specify "--enable-slirp".

But the error message is not very helpful. It should rather say something 
like (partly suggested by Daniel in IRC yesterday already):

 Type 'user' is not a supported netdev backend by this QEMU build. Please 
check the spelling or whether it has been enabled at compilation time.

... or something like this.

Someone interested to write a patch?

 Thomas