troubleshooting.md

Q: QtCreator imports my build successfully but shows almost all headers as absent.

A: This may be the case when the selected build directory uses a non-standard C compiler (such as afl-clang-fast). Just initialize a fresh build directory with some casual system-wide gcc/clang as CC, then re-import the project.

Q: A harness initializes LKL successfully, then fails to accept any input.

A: LKL can be configured roughly like the regular Linux kernel. This means, say, bpffuzz may initialize LKL successfully and then fail with ENOSYS from LKL because the bpf() syscall was disabled in LKL config. See this document for details.

Q: What kernel command line should I specify as the first argument for most harnesses?

A: Basically, mem=32M (or 128M, or other value depending on the task) should be enough. If you would like to pass any additional arguments to the kernel, make sure all they belong to the same argv[] element. When running a harness from bash, this can be accomplished with something like ./fsfuzz "mem=32M other.arg=1" ext4 btrfs