I've used Openbsd before but my installs have gone smoothly with no issues and this is really the first time it's been a problem. The install is a super boring one, it's whole disk Openbsd with the default gpt partition layout and nothing else special.
During the install after the sets are successfully installed there's a notification that the bootloader has failed to install due to mkdir being called with an invalid argument. Some research online said that I should try to do installboot manually in the subsequent prrompt, so I called installboot sd0 and got the following error installboot: /usr/mdec/biosboot: No such file or directory Looking in /usr/medc/ the only program is mbr. Using installboot -v I saw that the second stage is supposed to be /usr/medc/boot which is also missing. It's my understanding anyway that these are for mbr legacy boot situations not gtp efi ones and Mac's use efi so I don't know if this is the issue. So I really don't know where to go from here. I saw a few other references in the mailing list to missing biosboot but they don't seem relevant to this case as it seems like they had other issues as well. I don't know if it's an Mac efi problem or not but I've noticed that lots of the community use(d) Macbooks including airs but I didn't notice any specific things to do when installing. Sorry if I've missed something obvious, I've actually never had any trouble with the install before so it's my first time actually trying to work out what's up. I just have no clue how to debug this issue so any pointers would be much appreciated.