We use a couple nice home-grown functions in ZFSBootMenu to help debug things. We have a zdebug logging function that's peppered liberally throughout the code b

We use a couple nice home-grown functions in ZFSBootMenu to help debug things. We have a zdebug logging function that's peppered liberally throughout the code base - https://github.com/zbm-dev/zfsbootmenu/blob/master/zfsbootmenu/lib/kmsg-log-lib.sh#L16-L38 https://github.com/zbm-dev/zfsbootmenu/blob/master/zfsbootme... Hitting ctrl-t on our main menu will, when booting with debug logging enabled, show a screen like this: https://i.imgur.com/Ge75zkP.png https://i.imgur.com/Ge75zkP.png We also have a flamegraph profiling mechanism that can be enabled with https://github.com/zbm-dev/zfsbootmenu/blob/master/zfsbootmenu/profiling/profiling-lib.sh https://github.com/zbm-dev/zfsbootmenu/blob/master/zfsbootme... . That will dump data to a serial port, which when re-assembled, can be used to produce a graph like https://raw.githubusercontent.com/zbm-dev/zfsbootmenu/master/media/flamechart-v1.12.svg https://raw.githubusercontent.com/zbm-dev/zfsbootmenu/master... Bash is suprisingly flexible.