Bug#1143623: libfwupd-dev fails to coinstall

Hi Simon,

clearly I have no idea about gobject-introspection, and I'm not into 
this bug per se, but I was wondering...

On Mon, Aug 10, 2026 at 01:21:58PM +0100, Simon McVittie wrote:
> 3. (Longer term) Fix whatever upstream issue is causing the header files
>    to be mis-parsed by GObject-Introspection, so that Fwupd-2.0.gir is
>    the same on every architecture. Looking at the diff between amd64 and
>    i386, it seems like the various enums are not being introspected
>    correctly, with constants showing up as having value -1 on amd64
>    but 0 on i386, where their real value is G_MAXUINT64:
> 
>    --- gir1.2-fwupd-2.0_2.1.7-3_amd64/usr/share/gir-1.0/Fwupd-2.0.gir	2026-08-09 23:35:51.000000000 +0100
>    +++ gir1.2-fwupd-2.0_2.1.7-3_i386/usr/share/gir-1.0/Fwupd-2.0.gir	2026-08-09 23:35:51.000000000 +0100
>    @@ -14168,7 +14168,7 @@
>                  line="270">The device doesn't require verification of the newly installed version.</doc>
>           </member>
>           <member name="unknown"
>    -              value="-1"
>    +              value="0"
>                   c:identifier="FWUPD_DEVICE_FLAG_UNKNOWN">
>             <doc xml:space="preserve"
>                  filename="libfwupd/fwupd-device-struct.h"
> 
>    It looks like libfwupd is doing things that are not compatible with
>    the assumption made by GLib's GType system: it's setting the UNKNOWN
>    value for various enums to G_MAXUINT64, but the GFlagsValue data
>    structure represents members of a set of flags as guint (an alias for
>    unsigned int, 32 bits on all Debian platforms), so this is simply not
>    representable in the GType system. If you want these sets of flags to
>    be representable by the GType system and usable by GObject-Introspection
>    languages, then they will need to be limited to 32 bits wide (which would
>    be an ABI break).

... should gobject-introspection fail on such things? It seems to me 
that such a type violation would be a hard fail in other language 
ecosystems.

Silently producing different results on different archs for 
something that is not representable in the first place, sounds, 
excuse me, bad?

So - maybe this is all correct and I just lack context/understanding 
of why. If this is the case, please feel free to disregard my email.

Best,
Chris