Latest ebuild of telepathy-mission-control (5.16.2) fails to merge. build.log & emerge --info attached.
No flags are on for that ebuild:
USE="-debug -networkmanager -systemd"

UpSleepKind it seems was a enum declared in upower < 0.99 libupower-glib
libupower-glib/up-types.h:
103 typedef enum

{ 104 UP_SLEEP_KIND_UNKNOWN, 105 UP_SLEEP_KIND_SUSPEND, 106 UP_SLEEP_KIND_HIBERNATE, 107 UP_SLEEP_KIND_HYBRID, 108 UP_SLEEP_KIND_LAST 109 }

UpSleepKind;

NEWS file from 0.99 upower:
20 Feature Removals:
21 - Remove battery recall support (Bastien Nocera)
22 - Remove QoS support (Bastien Nocera)
23 - Remove OnLowBattery property (use WarningLevel instead) (Bastien Nocera)
24 - Remove DeviceChanged and Changed signals (PropertiesChanged
25 signals are sent instead) (Bastien Nocera)

QoS removal includes removal of UpSleepKind enum.