Rebuld yocto: split_and_strip_files error

Getting this error executing USE_DOCKER=1 make image_bin:

ERROR: linux-quic-3.18.140-r1 do_package: objcopy failed with exit code 1 (cmd was 'arm-poky-linux-gnueabi-objcopy' --only-keep-debug '/home/paul/yocto-mangOH-wp77xx/build_bin/tmp/work/swi_mdm9x28_wp-poky-linux-gnueabi/linux-quic/3.18.140-r1/package/usr/src/kernel/scripts/kconfig/mconf' '/home/paul/yocto-mangOH-wp77xx/build_bin/tmp/work/swi_mdm9x28_wp-poky-linux-gnueabi/linux-quic/3.18.140-r1/package/usr/src/kernel/scripts/kconfig/.debug/mconf'):
arm-poky-linux-gnueabi-objcopy:/home/paul/yocto-mangOH-wp77xx/build_bin/tmp/work/swi_mdm9x28_wp-poky-linux-gnueabi/linux-quic/3.18.140-r1/package/usr/src/kernel/scripts/kconfig/mconf: File format not recognized
ERROR: linux-quic-3.18.140-r1 do_package: Function failed: split_and_strip_files
ERROR: Logfile of failure stored in: /home/paul/yocto-mangOH-wp77xx/build_bin/tmp/work/swi_mdm9x28_wp-poky-linux-gnueabi/linux-quic/3.18.140-r1/temp/log.do_package.22872
ERROR: Task (/home/paul/yocto-mangOH-wp77xx/meta-swi/meta-swi-mdm9x28/recipes-kernel/linux/linux-quic_git.bb:do_package) failed with exit code '1'

Tried adding INHIBIT_PACKAGE_STRIP=“1” to ./build_bin/conf as suggested in another forum but get same error. Has anyone else seen this? Thanks.