There have been quite a few changes in the last week or two. The main change is that the nightlies are now being built on Debian stretch. In order to run the nightlies you will first need to upgrade the OS to stretch.
Make sure you have a backup. Once the upgrade starts there is no going back.
Once the upgrade has been completed you will need to also complete the following:
Edit
sudo nano /etc/apt/sources.list
The Stretch upgrade should have already commented out (Make sure this is the case)
Then add
deb Index of /osmc/osmc/download/dev/gmc-18 gmc-18 main
Save and exit file.
Import gpg certificate:
wget -qO - http://download.osmc.tv/dev/gmc-18/gpg.key | sudo apt-key add -
Finally run update and dist-upgrade to install latest nightly.
sudo apt-get update
sudo apt-get dist-upgrade
17.8-138, 4 Dec 2017: Based off OSMC commit (c8faceb4) and xbmc (3a9b8273)
XBMC:
[Music]Fix cancelling of music library export (PR:13105, 2 commits, 5 files changed)
[PVR] CPVRClient(s): Some more improvements (PR:13113, 3 commits, 4 files changed)
remove accidential left-over prototype (PR:13108, 1 commit, 1 file changed)
[MediaManager/gui] Cache disc label (PR:13107, 2 commits, 2 files changed)
VideoPlayer: drop some outdated and unsafe(threading) code (PR:13110, 1 commit, 9 files changed)
[videoplayer] Show stream flags in the gui and some fixes/improvements. (PR:13058, 10 commits, 34 files changed)
[PVR] Cleanup: No more GUI stuff in class CPVRTimerInfoTag (PR:13098, 2 commits, 9 files changed)
pvr.argustv:
add account info for smb shares (PR:76, 1 commit, 7 files changed)
jsoncpp1.8.3 deprecated function update (PR:77, 1 commit, 4 files changed)
Includes latest addons: inputstream.adaptive (d2081b2), inputstream.rtmp (c772497, +1), peripheral.joystick (33b43ce), pvr.argustv (1a48789, +2), pvr.demo (94c4817, +1), pvr.dvblink (816f90c), pvr.dvbviewer (6129441), pvr.filmon (2dee2ca), pvr.hdhomerun (3af3e91), pvr.hts (67fe2df), pvr.iptvsimple (ac4f4bd), pvr.mediaportal.tvserver (6c35e88), pvr.mythtv (ffaa1b5), pvr.nextpvr (938bb48), pvr.njoy (4a5efef), pvr.octonet (c4af00a), pvr.pctv (6484615), pvr.stalker (44025a1), pvr.teleboy (e431126), pvr.vbox (619c32b), pvr.vdr.vnsi (0ec3e77), pvr.vuplus (7ea6b21), pvr.wmc (55e701b), pvr.zattoo (23d9993)