Here it is:
$this->bbcode_second_pass_code('', '[root@alarmpi ~]# dmesg | tail
[ 11.911229] smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
[ 11.923505] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 12.051163] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 12.808523] EXT4-fs (sda2): mounted filesystem with ordered data mode. Opts: (null)
[ 13.422972] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 13.441831] smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1
[ 74.526682] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 106.526574] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 118.046572] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 129.566640] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[root@alarmpi ~]# dmesg | grep i2c
[ 8.376799] i2c-bcm2835 3f805000.i2c: Could not read clock-frequency property
[ 9.886661] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 12.051163] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 74.526682] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 106.526574] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 118.046572] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 129.566640] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 171.808367] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 193.569415] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
[ 205.089877] i2c-bcm2835 3f805000.i2c: i2c transfer timed out
')
Nothing is connected to my Pi 3 i2c bus. Again, this doesn't happen every time but when it happens, dmesg will be flooded with these "i2c transfer timed out" messages continuously. The good thing is one or two reboots will make it go away.