I was only able to recreate in curtin environment which has overlay root:
$ mount
overlayroot on / type overlayfs (rw,lowerdir=/media/root-ro/,upperdir=/media/root-rw/overlay)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
none on /sys/fs/pstore type pstore (rw)
/dev/sdf on /media/root-ro type ext4 (ro)
tmpfs-root on /media/root-rw type tmpfs (rw,relatime)
systemd on /sys/fs/cgroup/systemd type cgroup (rw,noexec,nosuid,nodev,relatime,name=systemd)
Attached are process_dump files for strace -o process_dump -ff apt-get install libc6
I was only able to recreate in curtin environment which has overlay root:
$ mount /media/ root-ro/ ,upperdir= /media/ root-rw/ overlay) nosuid, nodev) nosuid, nodev) fuse/connection s type fusectl (rw) security type securityfs (rw) nosuid, gid=5,mode= 0620) nosuid, size=10% ,mode=0755) nosuid, nodev,size= 5242880) nosuid, nodev,size= 104857600, mode=0755) cgroup/ systemd type cgroup (rw,noexec, nosuid, nodev,relatime, name=systemd)
overlayroot on / type overlayfs (rw,lowerdir=
proc on /proc type proc (rw,noexec,
sysfs on /sys type sysfs (rw,noexec,
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,
tmpfs on /run type tmpfs (rw,noexec,
none on /run/lock type tmpfs (rw,noexec,
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,
none on /sys/fs/pstore type pstore (rw)
/dev/sdf on /media/root-ro type ext4 (ro)
tmpfs-root on /media/root-rw type tmpfs (rw,relatime)
systemd on /sys/fs/
Attached are process_dump files for strace -o process_dump -ff apt-get install libc6