Error when upgrading jail from 12.1 to 12.2

A bug report has been filed upstream: https://github.com/iocage/iocage/issues/1228 

I thought you contributed back upstream issues and fixes? This is a bug in the function that TrueNAS uses that even if I haven't found a issue caused by it will likely eventually result in a problem. Parts of the update process are not completing by it's own report.

I concur, though they are not fatal, and this is simply a freebsd-update mechanism, not something we can handle.

There is a entire list of updates that it lists as unable to install:

Installing updates...install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/stand/common/readin.h: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/stand/common/vdisk.c: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/stand/efi/boot1/proto.c: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/stand/efi/boot1/proto.h: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/stand/efi/libefi/efihttp.c: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/tests/sys/net/if_epair.c: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/tools/boot/ci-qemu-test.sh: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/clang/llvm-objcopy/llvm-objcopy.1: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_dflag_a_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_dflag_a_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_dflag_b_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_dflag_b_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_dflag_c_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_dflag_c_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_oflag_a_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_oflag_a_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_oflag_b_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_oflag_b_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_oflag_c_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_oflag_c_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_xflag_a_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_xflag_a_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_xflag_b_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_xflag_b_el.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_xflag_c_eb.out: No such file or directory
install: /mnt/grandmama/iocage/jails/transmission/root//usr/src/usr.bin/hexdump/tests/d_hexdump_xflag_c_el.out: No such file or directory

If these did not need to occur, it seems illogical that the update process would include them? 

Thats definitely not the case. The extra / causes not issues at all, thats very common in UNIX.

Seems like these errors are not fatal and upgrade completed.