stress_mt failures on Linux and stuck on macOS

[tormodvolden]

We have previously seen errors on macOS on virtual machines, but here we have something I can reproduce. Testing on a Lenovo L13 with Intel i5-1135G7 (8 cores), Ubuntu 24.04 and its kernel 6.8.1, I get with 1.0.27 or latest git (last tested at 2a138c6):

Running multithreaded init/exit test...
Starting 8 threads
Running multithreaded init/exit test with enumeration...
Starting 8 threads
No access to device 1d6b:0003, skipping transfer tests.
No access to device 06cb:00bd, skipping transfer tests.
No access to device 13d3:56bc, skipping transfer tests.
No access to device 192f:0416, skipping transfer tests.
No access to device 04d9:1829, skipping transfer tests.
No access to device 05e3:0608, skipping transfer tests.
No access to device 05e3:0608, skipping transfer tests.
No access to device 046d:0a56, skipping transfer tests.
No access to device 8087:0026, skipping transfer tests.
No access to device 1d6b:0002, skipping transfer tests.
No access to device 1d6b:0003, skipping transfer tests.
No access to device 1d6b:0002, skipping transfer tests.
Thread 2 failed (iteration 1): LIBUSB_ERROR_IO
Thread 3 failed (iteration 1): LIBUSB_ERROR_IO
Thread 5 failed (iteration 1): LIBUSB_ERROR_IO
All threads discovered 13 devices (12 not opened)
All done, 3 errors

Or

Running multithreaded init/exit test...
Starting 8 threads
Running multithreaded init/exit test with enumeration...
Starting 8 threads
No access to device 1d6b:0003, skipping transfer tests.
No access to device 06cb:00bd, skipping transfer tests.
No access to device 13d3:56bc, skipping transfer tests.
No access to device 192f:0416, skipping transfer tests.
No access to device 04d9:1829, skipping transfer tests.
No access to device 05e3:0608, skipping transfer tests.
No access to device 05e3:0608, skipping transfer tests.
No access to device 046d:0a56, skipping transfer tests.
No access to device 8087:0026, skipping transfer tests.
No access to device 1d6b:0002, skipping transfer tests.
No access to device 1d6b:0003, skipping transfer tests.
No access to device 1d6b:0002, skipping transfer tests.
Thread 0 failed (iteration 1): LIBUSB_ERROR_IO
Device count mismatch: Thread 1 discovered 13 devices instead of 0
Thread 2 failed (iteration 1): LIBUSB_ERROR_IO
Thread 7 failed (iteration 1): LIBUSB_ERROR_IO
All done, 4 errors