After upgrading my home router/NAS from FreeBSD 14.4 to 14.5 I noticed some Ports crashing during configuration with "Illegal instruction". It seems to affect those Ports who use CMake during configuration like devel/pcre2.

root@gatekeeper:/usr/ports/devel/pcre2 # make
===>   pcre2-10.48 depends on file: /usr/local/bin/cmake - found
===>   pcre2-10.48 depends on executable: ninja - found
===>   pcre2-10.48 depends on package: pkgconf>=1.3.0_1 - found
===>  Configuring for pcre2-10.48
===>  Performing out-of-source build
/bin/mkdir -p /usr/ports/devel/pcre2/work/.build
-- Using CMake version 3.31.12 (/usr/local/bin/cmake)
-- The C compiler identification is Clang 21.1.8
Illegal instruction (core dumped)
*** Error code 132
<snip>

Looking at the core dump it points to security/rhash.

root@gatekeeper:/usr/ports/devel/pcre2/work/.build # gdb /usr/local/bin/cmake -c cmake.core
<snip>
Program terminated with signal SIGILL, Illegal instruction.
Privileged opcode.
#0  0x000000082512c7e4 in ?? () from /usr/local/lib/librhash.so.1

Unfortunately I'm unable to disassemble that frame to check exactly what instruction was used, because I don't know how to produce the needed debug symbols. I'm willing to try it if someone can help me with the necessary commands. But I had a look at the output from compiling security/rhash and there I see an explicit -msse4 sent to every cc line and I have no configurable option to disable this what I can find.

cc -c -DRHASH_SSE4_SHANI -DOPENSSL_RUNTIME -DNDEBUG -pipe -ffunction-sections -fdata-sections -fomit-frame-pointer -msse4 -msha -Wall -W -Wstrict-prototypes -Wnested-externs -Winline -Wpointer-arith -Wbad-function-cast -Wmissing-prototypes -Wmissing-declarations -O2 -pipe -fstack-protector-strong -isystem /usr/local/include -fno-strict-aliasing sha3.c -o sha3.o

If I add CPUTYPE?=x86-64 to /etc/make.conf the compiler adds -march=x86-64 as expected but it doesn't remove the -msse4 so unfortunately it doesn't help.

cc -c -DRHASH_SSE4_SHANI -DOPENSSL_RUNTIME -DNDEBUG -pipe -ffunction-sections -fdata-sections -fomit-frame-pointer -msse4 -msha -Wall -W -Wstrict-prototypes -Wnested-externs -Winline -Wpointer-arith -Wbad-function-cast -Wmissing-prototypes -Wmissing-declarations -O2 -pipe -march=x86-64 -fstack-protector-strong -isystem /usr/local/include -fno-strict-aliasing sha3.c -o sha3.o

My hardware is old but as I understand it should still be supported by FreeBSD and I did not run into this problem on 14.4.

CPU: Intel(R) Atom(TM) CPU D525   @ 1.80GHz (1800.09-MHz K8-class CPU)
  Origin="GenuineIntel"  Id=0x106ca  Family=0x6  Model=0x1c  Stepping=10
  Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
  Features2=0x40e31d<SSE3,DTES64,MON,DS_CPL,TM2,SSSE3,CX16,xTPR,PDCM,MOVBE>
  AMD Features=0x20100800<SYSCALL,NX,LM>
  AMD Features2=0x1<LAHF>
  TSC: P-state invariant, performance statistics

The version of security/rhash is the same as I used on FreeBSD 14.4 so maybe this instead points to some incompatibility with the upgraded Clang that came with FreeBSD 14.5?

Eventually I will have to replace my hardware but if this is a bug I would prefer not having to replace the hardware with the currently inflated prices on RAM and SSD :-)
Please let me know if I can provide any other information from my system to help resolve this.

Regards
Morgan Wesström