If you are planning on distributing alpha builds yourself, take a look at the patches/{glib, gobject-introspection) directories in the Buildstream snapshot as those are required fixes that we merged but haven’t released another version of the respective projects since.
In general, I would suggest using git snapshots if you can for glib and gobject-introspection as there are a couple more fixes that have landed. There will be new tarball releases soon enough as well, 46.beta is not that far of either!
Additionally, take a look at this thread for how to build GLib and G-I for GNOME 46.