I have been using a number of Raspberry Pi 4 devices running Raspbian Buster with the standard packaged version of Supercollider (3.10.0) sound synth for some time. Last week, an 'apt update & upgrade' stopped them all from working. This only affected the Raspberry Pi OS as the other versions on ubuntu (amd/intel) all continued to function. Installing ubuntu on the RPi4 was partially successful, but the sound output was badly distorted.
I could not find out whether it was a problem with Supercollider, Jackd or an updated OS file that either one of Supercollider or Jackd rely on. I tried a weeks' worth of fixes and solutions found elsewhere on the interweb, none worked, although error messages were similar.
I have finally got myself back to square one by reimaging with 2020-08-20-raspios-buster-armhf-full.img and NOT updating anything with 'apt update/upgrade'.
If anyone is interested in this issue being resolved and are able to provide me some useful tips on upgrading a bit at a time or comparing the files in two debian images, please let me know. Otherwise I will just continue with this old OS version and hope someone else fixes this issue before I have to apt update. Anyone else with this issue, I hope that knowing that 2020-08-20-raspios-buster is a potential solution will be of use to you.
I have tried so, so many different solutions and absolutely nothing worked, so no more suggestions like that please.
Here are the consistent error messages for users seraching:-
JackPosixProcessSync::LockedTimedWait error usec = 5000000 err = Connection timed out
Driver is not running
Cannot read socket fd = 5 err = Success
Cannot create new client
CheckRes error
JackSocketClientChannel read fail
Cannot open SuperCollider client
JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
terminate called without an active exception
could not initialize audio.
ALSA: poll time out, polled for 34828070 usecs
JackAudioDriver::ProcessAsync: read error, stopping...