The deprecated construct '@0@'.format(h) (where h is a file object)
expanded to the filename relative to the project root, which in this
particular case happens to be what we wanted:
`--c-include=gio/gunixmounts.h` resulted in a recommendation to
`#include <gio/gunixmounts.h>` and so on. Replacing it with
h.full_path() resulted in GIR XML and documentation that recommended
constructs like `#include </home/me/src/glib/gio/gunixmounts.h>`,
which is not what was intended (and caused new differences between
different architectures' Gio-2.0.gir on multiarch systems, which is
how I discovered this).
Hard-coding `gio/` and appending the basename of the header seems like
the simplest non-deprecated spelling that will do what we wanted.
Fixes: 51e3e7d9 "build: Bump Meson dependency to 1.4.0"
Resolves: https://gitlab.gnome.org/GNOME/glib/-/issues/3564
Signed-off-by: Simon McVittie <smcv@collabora.com>
feca93e51e