FreeBSD-main-amd64-test - Build #24919 - Still Unstable

FreeBSD-main-amd64-test - Build #24919 (a650ec0e55a9e0511321fd3e311bbd3aa46bcb12) - Still Unstable

Build information: https://ci.FreeBSD.org/job/FreeBSD-main-amd64-test/24919/
Full change log: https://ci.FreeBSD.org/job/FreeBSD-main-amd64-test/24919/changes
Full build log: https://ci.FreeBSD.org/job/FreeBSD-main-amd64-test/24919/console

Status explanation:
"Unstable" - some tests are suspected being broken by the following changes
"Still Unstable" - the failing test cases have not been fixed by these
                   following changes and this is a notification to note that
                   these changes have not been fully tested by the CI system

Change summaries:
(Those commits are likely but not certainly responsible)

0724293331e4c35c0a8cc5b8922a153545725c24 by kib:
nullfs_mount(): remove unneeded cast

8921216dbee6884532e22d5347cff4d9ed23e782 by kib:
nullfs: add -o cache

4a2a69c4472cf677f8dfc026fff3dd33c83580cb by kib:
mount_nullfs(8): document -o cache and vfs.nullfs.cache_vnodes

4e8d264b0057e80ed2c1086da30d5e2391d82ffc by kib:
nullfs_mount(): fix whitespace

a650ec0e55a9e0511321fd3e311bbd3aa46bcb12 by brooks:
lib{c,sys}: fix incremental builds



The failed test cases:

2 tests failed.
FAILED:  sys.kern.ptrace_test.ptrace__follow_fork_child_detached_unrelated_debugger

Error Message:
/usr/src/tests/sys/kern/ptrace_test.c:591: WIFSTOPPED(status) not met

FAILED:  cddl.usr.sbin.zfsd.zfsd_unittest.main

Error Message:
Received signal 6