caused by missing \ after ARCH=
ie from last kernel module build on builders (lin_tape for 6.6.7 on x86_64):
+ /usr/bin/make -Otarget -j28 -C /usr/src/linux-4.19 clean 'RCS_FIND_IGNORE=-name '\''*.[ks]o'\'' -o' 'M=/tmp/B.a91ebdxq/BUILD/lin_tape-3.0.60' 'HOSTCC=x86_64-pld-linux-gcc' 'SYSSRC=/usr/src/linux-4.19' 'SYSOUT=/tmp/B.a91ebdxq/BUILD/lin_tape-3.0.60/o' 'ARCH=x86_64'
+ CC=x86_64-pld-linux-gcc
+ /usr/bin/make -Otarget -j28 -C /usr/src/linux-4.19 modules 'M=/tmp/B.a91ebdxq/BUILD/lin_tape-3.0.60' 'CONSTIFY_PLUGIN=' 'HOSTCC=x86_64-pld-linux-gcc' 'SYSSRC=/usr/src/linux-4.19' 'SYSOUT=/tmp/B.a91ebdxq/BUILD/lin_tape-3.0.60/o' 'ARCH=x86_64'
CC [M] /tmp/B.a91ebdxq/BUILD/lin_tape-3.0.60/fo_util.o
...
LD [M] /tmp/B.a91ebdxq/BUILD/lin_tape-3.0.60/lin_tape.ko
+ CC=x86_64-pld-linux-gcc
...
ARCH=%{_target_base_arch} CROSS_COMPILE=%{_target_cpu}-pld-linux- \\\
%endif \\\
%else \\\
- ARCH=%_kernel_arch \\\
+ ARCH=%_kernel_arch \\\\\\\
CC="%{__cc}" \\\
%endif \
%define MakeOpts HOSTCC="%{__cc}" SYSSRC=%{_kernelsrcdir} SYSOUT=$PWD/o \\\\\\\