The [HACKING](https://github.com/geany/geany/blob/master/HACKING) file has this:
Geany requires GTK >= 2.24 and GLib >= 2.32.
but also this:
Your code should build against GLib 2.27.3
and this:
You might want to pass the `-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_28` C
preprocessor flag to get warnings about newer symbols from the GLib.
So which is it? 2.32 or 2.28/2.27?