There are several issues with writing to a debug log file when fuzzing:

    Disk access is slow, but fuzzing should be fast (Note: I could not
verify this claim with data)
    Disks have a limited size and will eventually run out of space, but
fuzzing should run continuous

Fix both issues by disabling the debug log file for fuzz tests

ninja all check

ninja bitcoin-fuzzers
./test/fuzz/test_runner.py <path_to_corpus>