Big compat issue with a recent current (zfs + syscall)

Hi,

I tried to update from -current as of 2025-08-11-154054 (CEST) to 
2025-08-20-075320. I've updated the kernel and base, but no jail. 
Result:

1) Not all jails got up. For mysql I have the DB on a separate dataset, 
I attach the dataset to the jail (grep dataset /etc/rc.d/jail) to be 
able to manage it from within the jail. I got the message that the 
dataset is already attached (first start of the jail at boot). When I 
resolved this by simply not attaching the dataset, mysqld died with a 
bad syscall.

2) A lot of processes inside jails segfaulted.

I then updated the jails from the build. More processes came up, but 
some still died (e.g. php_fpm).

At that point I reverted all back (this emails is handled via the jails 
on this host). I still have the BE which causes issues, in case someone 
needs to get some info out of it.

I have not seen anything in UPDATING which suggests anything in this 
regard.

src.conf:
---snip---
WITHOUT_PROFILE=yes
CFLAGS+=-DFTP_COMBINE_CWDS
MALLOC_PRODUCTION=yes
WITH_MALLOC_PRODUCTION=yes
WITHOUT_LLVM_ASSERTIONS=yes
KERNCONF=ANDROMEDA
WITH_RETPOLINE=yes
WITH_KERNEL_RETPOLINE=yes
WITH_RELRO=yes
WITH_BIND_NOW=yes
OPT_INIT_ALL=zero
WITH_ZEROREGS=yes
WITHOUT_CLEAN=yes
LOADER_GZIP_SUPPORT=no
LOADER_BZIP2_SUPPORT=no
LOADER_BIOS_TEXTONLY=no
LOADER_NFS_SUPPORT=no
LOADER_TFTP_SUPPORT=no
LOADER_CD9660_SUPPORT=no
---snip---

src-env.conf:
---snip---
WITH_META_MODE=yes
FORTIFY_SOURCE=2
---snip---

Bye,
Alexander.

-- 
http://www.Leidinger.net Alexander@Leidinger.net: PGP 0x8F31830F9F2772BF
http://www.FreeBSD.org    netchild@FreeBSD.org  : PGP 0x8F31830F9F2772BF