The issue you are currently experiencing with OSMC
Enabling SPI in “My OSMC” does not work on the Raspberry Pi 2/3. The devices /dev/spidev0.0 and /dev/spidev0.1 do not show up after a reboot.
What you were doing when this issue occurred
I ticked the SPI checkbox in “My OSMC”.
Whether you can replicate this issue on demand. If you can, then please provide some steps on how an OSMC developer can reproduce the same issue.
Yes, replication is easy. Tick the SPI checkbox in “My OSMC” and reboot. /dev/spidev0.0 and /dev/spidev0.1 will not show up.
The device you are currently running OSMC on
Raspberry Pi 2B and Raspberry Pi 3B (same issue on both)
What peripherals are attached to the device?
TV via HDMI, Network via LAN port.
Has this issue been introduced by a new version of OSMC? When did the issue first appear and can you recall a time when it was not present?
This has been broken since November 2015 according to https://discourse.osmc.tv/t/dev-spidev0-0-missing-after-november-update/10622.
Solution: “My OSMC” should not set dtoverlay=spi-bcm2835-overlay in /boot/config.txt, but it should set dtparam=spi=on instead.