Decoding mismatches with >1 tile threads on a sample with two tile cols

tiles.ivf

$ ./dav1d --framethread 4 --tilethread 2 -i tiles.ivf --muxer md5 -o -
d59361a49fdb99d7a10038f9a45b47da
dav1d 0.0.1 - by VideoLAN
Decoded 1/24 frames (4.2%)
Decoded 2/24 frames (8.3%)
Decoded 3/24 frames (12.5%)
Decoded 4/24 frames (16.7%)
Decoded 5/24 frames (20.8%)
Decoded 6/24 frames (25.0%)
Decoded 7/24 frames (29.2%)
Decoded 8/24 frames (33.3%)
Decoded 9/24 frames (37.5%)
Decoded 10/24 frames (41.7%)
Decoded 11/24 frames (45.8%)
Decoded 12/24 frames (50.0%)
Decoded 13/24 frames (54.2%)
Decoded 14/24 frames (58.3%)
Decoded 15/24 frames (62.5%)
Decoded 16/24 frames (66.7%)
Decoded 17/24 frames (70.8%)
Decoded 18/24 frames (75.0%)
Decoded 19/24 frames (79.2%)
Decoded 20/24 frames (83.3%)
Decoded 21/24 frames (87.5%)
Decoded 22/24 frames (91.7%)
Decoded 23/24 frames (95.8%)
Decoded 24/24 frames (100.0%)

$ ./dav1d --framethread 4 --tilethread 2 -i tiles.ivf --muxer md5 -o -
69df623c74245a445bb6760f65aa0abd
dav1d 0.0.1 - by VideoLAN
Decoded 1/24 frames (4.2%)
Decoded 2/24 frames (8.3%)
Decoded 3/24 frames (12.5%)
Decoded 4/24 frames (16.7%)
Decoded 5/24 frames (20.8%)
Decoded 6/24 frames (25.0%)
Decoded 7/24 frames (29.2%)
Decoded 8/24 frames (33.3%)
Decoded 9/24 frames (37.5%)
Decoded 10/24 frames (41.7%)
Decoded 11/24 frames (45.8%)
Decoded 12/24 frames (50.0%)
Decoded 13/24 frames (54.2%)
Decoded 14/24 frames (58.3%)
Decoded 15/24 frames (62.5%)
Decoded 16/24 frames (66.7%)
Decoded 17/24 frames (70.8%)
Decoded 18/24 frames (75.0%)
Decoded 19/24 frames (79.2%)
Decoded 20/24 frames (83.3%)
Decoded 21/24 frames (87.5%)
Decoded 22/24 frames (91.7%)
Decoded 23/24 frames (95.8%)
Decoded 24/24 frames (100.0%)

$ ./dav1d --framethread 4 --tilethread 2 -i tiles.ivf --muxer md5 -o -
4a5560520c92668226c7111f57fa9df4
dav1d 0.0.1 - by VideoLAN
Decoded 1/24 frames (4.2%)
Decoded 2/24 frames (8.3%)
Decoded 3/24 frames (12.5%)
Decoded 4/24 frames (16.7%)
Decoded 5/24 frames (20.8%)
Decoded 6/24 frames (25.0%)
Decoded 7/24 frames (29.2%)
Decoded 8/24 frames (33.3%)
Decoded 9/24 frames (37.5%)
Decoded 10/24 frames (41.7%)
Decoded 11/24 frames (45.8%)
Decoded 12/24 frames (50.0%)
Decoded 13/24 frames (54.2%)
Decoded 14/24 frames (58.3%)
Decoded 15/24 frames (62.5%)
Decoded 16/24 frames (66.7%)
Decoded 17/24 frames (70.8%)
Decoded 18/24 frames (75.0%)
Decoded 19/24 frames (79.2%)
Decoded 20/24 frames (83.3%)
Decoded 21/24 frames (87.5%)
Decoded 22/24 frames (91.7%)
Decoded 23/24 frames (95.8%)
Decoded 24/24 frames (100.0%)

First md5 is correct, the other two are wrong. You can get other md5 values if you keep running the above command, so this most likely a race.