A reply to https://gitlab.gnome.org/GNOME/gtkmm/-/issues/97 and https://discourse.gnome.org/t/in-compatibility-of-gtkmm-with-cairomm-pangomm-and-atkmm/6370?u=raghavgururajanand
The gtkmm developers have not (yet) started using
discourse.gnome.org. We still use the mailing list at
https://mail.gnome.org/archives/gtkmm-list.
The mailing list post
https://mail.gnome.org/archives/gtkmm-list/2020-December/msg00013.html
tries to explain the complicated relationships between the two
sets of module versions.
> [1] Why is gtkmm-3.24.4 incompatible with cairomm-1.16.0,
pangomm-2.48.0 and atkmm-2.36.0, as all of these are latest stable
releases?
There are two sets of ABI-incompatible versions of glibmm,
cairomm, pangomm and atkmm. It was decided long ago that the new
versions should not have their major version numbers bumped up,
because the underlying C modules (glib, cairo, pango and atk) have
not released ABI-incompatible versions, and thus have not bumped
their major versions. I'm not sure this was the best possible
decision, but now we have to live it.
The last versions that will be compatible with gtkmm-3.y.z are
glibmm-2.66.z, cairomm-1.14.z, pangomm-2.46.z and atkmm-2.34.z.
(There is no atkmm-2.34.z yet. Perhaps there will never be. The
maintenance of atkmm is really minimal.)
> [2] Will there be new release of gtkmm in 3.24 series, that
will be compatible with cairomm-1.16.0, pangomm-2.48.0 and
atkmm-2.36.0?
No, there will never be a gtkmm-3.y.z version compatible with
libsigc++-3.y.z, glibmm-2.68.z, cairomm-1.16.z, pangomm-2.48.z and
atkmm-2.36.z. They are compatible with gtkmm-4.y.z.