[arch-general] update of chroot fails - error: cannot remove file '/sys/': Read-only file system

[David C. Rankin]

Guys,

  Attempting to update an arch chroot (only a couple days old), I have run into
the following error:

sudo mkarchroot -u $CHROOT/root
:: Synchronizing package databases...
 core is up to date
 extra is up to date
 community is up to date
 local is up to date
:: Starting full system upgrade...
resolving dependencies...
looking for inter-conflicts...

Targets (12): dbus-core-1.6.0-4  e2fsprogs-1.42.4-1  filesystem-2012.6-4
hwids-20120611-1  iproute2-3.4.0-2
              iputils-20101006-3  kmod-9-1  libsystemd-185-2  libusbx-1.0.12-1
linux-3.4.4-2  systemd-tools-185-2
              xz-5.0.4-1

Total Installed Size:   71.36 MiB
Net Upgrade Size:       0.49 MiB

Proceed with installation? [Y/n]
(12/12) checking package integrity
[#######################################] 100%
(12/12) loading package files
[#######################################] 100%
(12/12) checking for file conflicts
[#######################################] 100%
error: cannot remove file '/sys/': Read-only file system
error: could not commit transaction
error: failed to commit transaction (transaction aborted)
Errors occurred, no packages were upgraded.

  How do I fix this? Is this another filesystem update issue like with
filesystem-2012.6-2?

-- 
David C. Rankin, J.D.,P.E.