A head -r317820 incremental buildworld race: kvm_geterr_test failures for -j16 but works without -j<?>

I've had reason to be experimenting with libkvm recently
and have repeatedly run into the following when doing
buildworld with -j16. (I tend to run full buildworlds even
for well-localized changes.) The context is having run
buildworld to completion before so the update is
incremental.

--- kvm_geterr_test ---
kvm_geterr_test.o: In function `atfu_kvm_geterr_negative_test_NULL_body':
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:56: undefined reference to `errbuf_has_error'
kvm_geterr_test.o: In function `atfu_kvm_geterr_positive_test_no_error_body':
. . .
--- kvm_geterr_test ---
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:108: undefined reference to `errbuf_clear'
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:109: undefined reference to `errbuf'
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:109: undefined reference to `errbuf'
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:110: undefined reference to `errbuf_has_error'
kvm_geterr_test.o: In function `atfu_kvm_geterr_positive_test_error_body':
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:73: undefined reference to `errbuf_clear'
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:74: undefined reference to `errbuf'
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:74: undefined reference to `errbuf'
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:75: undefined reference to `errbuf_has_error'
/usr/src/lib/libkvm/tests/kvm_geterr_test.c:80: undefined reference to `errbuf_has_error'

By contrast if I omit -j<?> completely the incremental
buildworld runs to completion just fine. (rm -rf of the
past buildworld and so building from scratch also works.)

The context for my activity happens to use:

# more ~/sys_build_scripts.amd64-host/make_powerpcvtsc_nodebug_gcc421_bootstrap_clang-amd64-host.sh 
kldload -n filemon && \
script ~/sys_typescripts/typescript_make_powerpcvtsc_nodebug_gcc421_bootstrap_clang-amd64-host-$(date +%Y-%m-%d:%H:%M:%S) \
env __MAKE_CONF="/root/src.configs/make.conf" SRCCONF="/dev/null" SRC_ENV_CONF="/root/src.configs/src.conf.powerpc-gcc421-bootstrap-clang.amd64-host" \
WITH_META_MODE=yes \
MAKEOBJDIRPREFIX="/usr/obj/powerpcvtsc_clang_gcc421" \
make $*

# more /root/src.configs/src.conf.powerpc-gcc421-bootstrap-clang.amd64-host
TO_TYPE=powerpc
#
KERNCONF=GENERICvtsc-NODBG
TARGET=${TO_TYPE}
.if ${.MAKE.LEVEL} == 0
TARGET_ARCH=${TO_TYPE}
.export TARGET_ARCH
.endif
#
WITH_CROSS_COMPILER=
WITHOUT_SYSTEM_COMPILER=
#
WITHOUT_LIBCPLUSPLUS=
WITH_BINUTILS_BOOTSTRAP=
WITH_ELFTOOLCHAIN_BOOTSTRAP=
WITHOUT_CLANG_BOOTSTRAP=
WITHOUT_CLANG=
WITHOUT_CLANG_IS_CC=
WITHOUT_CLANG_FULL=
WITHOUT_CLANG_EXTRAS=
WITHOUT_LLD=
WITHOUT_LLDB=
#
WITH_BOOT=
WITHOUT_LIB32=
#
WITH_GCC_BOOTSTRAP=
WITH_GCC=
WITH_GCC_IS_CC=
WITH_GNUCXX=
#
NO_WERROR=
#WERROR=
MALLOC_PRODUCTION=
#
WITH_REPRODUCIBLE_BUILD=
WITH_DEBUG_FILES=


===
Mark Millard
markmi at dsl-only.net