Undeclared dependency on gio-unix-2.0
## Submitted by Jan Tojnar
Assigned to **Ali Abdallah `@ali`**
**[Link to original bug (#14587)](https://bugzilla.xfce.org/show_bug.cgi?id=14587)**
## Description
I am building xfce4-power-manager 1.6.1 on NixOS and getting the following error:
```
make[3]: Entering directory '/build/xfce4-power-manager/src'
CC xfce4_power_manager-xfce-power-manager-dbus.o
CC xfce4_power_manager-xfpm-marshal.o
CC xfce4_power_manager-org.freedesktop.PowerManagement.o
CC xfce4_power_manager-org.freedesktop.PowerManagement.Inhibit.o
org.freedesktop.PowerManagement.Inhibit.c:16:12: fatal error: gio/gunixfdlist.h: No such file or directory
# include <gio/gunixfdlist.h>
^~~~~~~~~~~~~~~~~~~
compilation terminated.
make[3]: *** [Makefile:919: xfce4_power_manager-org.freedesktop.PowerManagement.Inhibit.o] Error 1
make[3]: *** Waiting for unfinished jobs....
xfce-power-manager-dbus.c:16:12: fatal error: gio/gunixfdlist.h: No such file or directory
# include <gio/gunixfdlist.h>
^~~~~~~~~~~~~~~~~~~
compilation terminated.
make[3]: *** [Makefile:877: xfce4_power_manager-xfce-power-manager-dbus.o] Error 1
org.freedesktop.PowerManagement.c:16:12: fatal error: gio/gunixfdlist.h: No such file or directory
# include <gio/gunixfdlist.h>
^~~~~~~~~~~~~~~~~~~
compilation terminated.
make[3]: *** [Makefile:905: xfce4_power_manager-org.freedesktop.PowerManagement.o] Error 1
make[3]: Leaving directory '/build/xfce4-power-manager/src'
make[2]: *** [Makefile:653: all] Error 2
make[2]: Leaving directory '/build/xfce4-power-manager/src'
make[1]: *** [Makefile:513: all-recursive] Error 1
make[1]: Leaving directory '/build/xfce4-power-manager'
make: *** [Makefile:445: all] Error 2
```
Version: 1.6.1
issue