Comment 6 for bug 23374

Hm, well, you're right (manually adding CONFIG_MAGIC_SYSRQ=y to the config file
and rebuilding didn't affect anything, but there's no mention of it in the
/boot/config-* file, which confused me), but unfortunately, I'm not able to get
the Magic SysRq key to work. Alt-sysrq-1 and altl-sysrq-t unfortunately behave
just like alt-1 and alt-t. (I've also tried the other permutations of ctrl and
alt, with no success)

For what it's worth, I also tried the magic sysrq key in a working kernel, and
with a different keyboard, to no effect.