I’m holding back on giving details at the moment, as I’ve discovered that although my build on a Pi4 running bustoer works fine, when I move the SD card to a Pi3 it freezes the computer during the Sonic Pi startup. Going to be quite difficult to debug as I haven’t yet found anything in the logs to indicate what is going wrong.
UPDATE IT turns out that the reason it “freezes” on a Pi3 is that the 3.2dev version seems to have grown in resource requirements and appears to need around 1Gb of ram to run at present. (This is true on Mac as well).
A temporary solution is to increase the swap file on the Buster SD card you are running on Pi3. I raised it from 90 to 1024 Mb. Not an ideal solution but it showed that it does run on a Pi3. I think some optimisation is probably possible (and certainly desirable) before 3.2dev is released. However 3.1 is fine.
I am now looking at the possibility fo producing a package that could be used for this.
For those wanting to build it SP3.1, the process is very similar to the build-debian-apt script in the sonic-pi/app/gui/qt folder on github. I build it for the tagged 3.1 release (a little later than the 3.0.1 tagged release) and also added a couple later “bug” resolutions which were added after that point. I built 3.9.1 plugins rather than the 3.9.0 used there. Also libaubio5 in the Buster distro is fine for aubio rather than building it and you can also use libqwt-qt5-dev instad of building qwt. Because Buster has ruby 2.5.5 you need a later rugged (I used the latest) and the bodge described in the script to install it. You need to uninstall the existing sonic-pi and related packages uncluding ruby and super-collider-server and then reinstall ruby, I don’t want to give full details yet until I’ve played with it a bit more and made some further refinements.
If you have a Pi4 (mine has 4Gb of RAM) then compiling is reasonably painless and much quicker than on previous models.