Re: Regressions in build process introduced since August

[Daniel P . Berrangé]

On Mon, Nov 23, 2020 at 03:40:48PM +0100, Stefan Weil wrote:
> Am 23.11.20 um 14:55 schrieb Paolo Bonzini:
> 
> > On 21/11/20 12:09, Stefan Weil wrote:
> > > --- a/meson.build
> > > +++ b/meson.build
> > > @@ -649,9 +649,8 @@ if get_option('vnc').enabled()
> > >     vnc = declare_dependency() # dummy dependency
> > >     png = dependency('libpng', required: get_option('vnc_png'),
> > >                      method: 'pkg-config', static: enable_static)
> > > -  jpeg = cc.find_library('jpeg', has_headers: ['jpeglib.h'],
> > > -                         required: get_option('vnc_jpeg'),
> > > -                         static: enable_static)
> > 
> > Does it work if you just remove "static: enable_static"?  That asks
> > Meson to look explicitly for a ".a" file instead of just adding a
> > "-ljpeg" flag.  However it is not what configure used to do so it
> > shouldn't be necessary.
> 
> 
> No, that does not help. Neither header file nor library will be found in my
> cross environment without using the provided --extra-cflags and
> --extra-ldflags, because all those files are installed below
> /usr/i686-w64-mingw32/sys-root/mingw or
> /usr/x86_64-w64-mingw32/sys-root/mingw which is not searched by the default
> compiler settings. The Meson checks obviously don't use those flags.
> 
> pkg-config provides the right paths and works therefore.

Relying on pkg-config should be our strong preference. I expect we're doing
the old fashioned library check just for historical reasons, but even RHEL-7
supports pkg-config for libjpeg. So I think we're safe to just unconditionally
rely on pkg-config these days and thus have it "just work" for cross compiles
too.


Regards,
Daniel
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