Combining the read-only rootfs template with the inetutils-ping6 package results in a build failure.
$ configure --enable-board=intel-x86-64 \
--enable-rootfs=glibc_std --enable-kernel=preempt_rt \
--with-template=feature/readonly-root \
--with-package=inetutils-ping6 --with-rcpl-version=0017
$ make fs
...
ERROR: Function failed: do_rootfs (log file is located at /usr/work/ro-rootfs/bitbake_build/tmp/work/intel_x86_64-wrs-linux/wrlinux-image-glibc-std/1.0-r5/temp/do_rootfs/log.do_rootfs.13931)
ERROR: Task 7 (/usr/work/ro-rootfs/layers/local/recipes-img/images/wrlinux-image-glibc-std.bb, do_rootfs) failed with exit code '1'
...