Undeclared dependency on gio-unix-2.0

I am building GNOME Flashback 3.28.0 on NixOS and getting the following error:

make[5]: Entering directory '/build/gnome-flashback-3.28.0/gnome-flashback/libaudio-device-selection'
  CC       libaudio_device_selection_la-gf-audio-device-selection.lo
  CC       libaudio_device_selection_la-gf-audio-device-selection-dialog.lo
  CC       libaudio_device_selection_la-gf-audio-device-selection-gen.lo
gf-audio-device-selection-gen.c:16:12: fatal error: gio/gunixfdlist.h: No such file or directory
 #  include <gio/gunixfdlist.h>
            ^~~~~~~~~~~~~~~~~~~
compilation terminated.
make[5]: *** [Makefile:552: libaudio_device_selection_la-gf-audio-device-selection-gen.lo] Error 1
make[5]: *** Waiting for unfinished jobs....
make[5]: Leaving directory '/build/gnome-flashback-3.28.0/gnome-flashback/libaudio-device-selection'
make[4]: *** [Makefile:448: all] Error 2
make[4]: Leaving directory '/build/gnome-flashback-3.28.0/gnome-flashback/libaudio-device-selection'
make[3]: *** [Makefile:765: all-recursive] Error 1
make[3]: Leaving directory '/build/gnome-flashback-3.28.0/gnome-flashback'
make[2]: *** [Makefile:556: all] Error 2
make[2]: Leaving directory '/build/gnome-flashback-3.28.0/gnome-flashback'
make[1]: *** [Makefile:530: all-recursive] Error 1
make[1]: Leaving directory '/build/gnome-flashback-3.28.0'
make: *** [Makefile:462: all] Error 2

Downstream issue: https://github.com/NixOS/nixpkgs/issues/36468