I notice from the makefile that main.o isn’t made for "make all" is it not required? This is what give the libc error.
I generated just the octopus.elf using "make all" I get the following file:
If you can cross check it with what is generated on your side (maybe?)
I compared this to the syx of OS 1.02 and it looks to be the same, minus the formatting for MIDI sysex.
The download link you give for the USB updating PDF doesn’t work (it redirects to main genoQs.com page). The same thing happens for the future music review PDF you have linked to on the website reviews section.