# DF-5474 — vkernel64 platform does not build: kern_mib __build_id_* unresolved (SYSTEM_LD drops ELDFLAGS and never uses the platform ldscript)

**File:** sys/platform/vkernel64/x86_64/db_trace.c audit, discovered at rig build time
**Severity:** Low (build regression / platform availability) · **Confidence:** certain

See VERDICT.md. Stock `make nativekernel KERNCONF=VKERNEL64` fails at
`linking kernel.debug` with undefined `__build_id_start/__build_id_end`:
kern.pre.mk:135 adds `--build-id=sha1` for all kernels, kern_mib.c references
the boundary symbols, pc64 provides them via its ldscript, vkernel64's
SYSTEM_LD override (conf/Makefile:23-25) drops `${ELDFLAGS}` and its own
ldscript is dead (vk_build3.log). fix.diff: defsym both symbols to 0 in
SYSTEM_LD (kern_mib then returns ENOENT gracefully). Validated: link + boot.

Build/run:
```
cd /usr/src && make nativekernel KERNCONF=VKERNEL64     # stock: fails (vk_build2.log)
patch -p1 < fix.diff && make nativekernel KERNCONF=VKERNEL64   # links (vk_fixbuild2.log)
```