Clarity For Use Of "--sysroot"

[vindicatorr]

I get the purpose, but am failing in implementing its use...
I narrowed down my issue to:
/usr/bin/dracut

   1392 [[ -d $dracutsysrootdir$systemdutildir ]] \
   1393     || systemdutildir=$(pkg-config systemd --variable=systemdutildir 2> /dev/null)
   1394 
   1395 if ! [[ -d $dracutsysrootdir$systemdutildir ]]; then
   1396     [[ -e $dracutsysrootdir/lib/systemd/systemd-udevd ]] && systemdutildir=/lib/systemd
   1397     [[ -e $dracutsysrootdir/usr/lib/systemd/systemd-udevd ]] && systemdutildir=/usr/lib/systemd
   1398 fi
   1399 
   1400 [[ -d $dracutsysrootdir$systemdutilconfdir ]] \
   1401     || systemdutilconfdir=$(pkg-config systemd --variable=systemdutilconfdir 2> /dev/null)
   1402 
   1403 [[ -d $dracutsysrootdir$systemdutilconfdir ]] || systemdutilconfdir=/etc/systemd
   1404 

Success:

$ sudo dracut \
--force \
--uefi \
--uefi-stub /usr/lib/systemd/boot/efi/linuxx64.efi.stub \
--kernel-image /usr/lib/modules/$(make -s kernelrelease)/vmlinuz \
--zstd \
--printsize \
--debug \
/boot/EFI/Linux/linux-$(make -s kernelrelease)-$(uname -m)-$(awk -F= '/BUILD_ID/{ print $2}' /etc/os-release)_test.efi \
$(make -s kernelrelease) 2>&1 | tee dracutsuccess.log

Fail:

$ sudo dracut \
--force \
--uefi \
--uefi-stub ${ROOT}/usr/lib/systemd/boot/efi/linuxx64.efi.stub \
--kernel-image ${ROOT}/usr/lib/modules/$(make -s kernelrelease)/vmlinuz \
--zstd \
--printsize \
--debug \
--sysroot ${ROOT} \
${ROOT}/boot/EFI/Linux/linux-$(make -s kernelrelease)-$(uname -m)-$(awk -F= '/BUILD_ID/{ print $2}' ${ROOT}/etc/os-release)_test.efi \
$(make -s kernelrelease) 2>&1 | tee dracutsysrootfail.log

Success Log:

    485 /usr/bin/dracut@1390(): outfile=/boot/EFI/Linux/linux-6.5.0-dirty-x86_64-rolling_test.efi
    486 /usr/bin/dracut@1392(): [[ -d '' ]]
    487 //usr/bin/dracut@1393(): pkg-config systemd --variable=systemdutildir
    488 /usr/bin/dracut@1393(): systemdutildir=/usr/lib/systemd
    489 /usr/bin/dracut@1395(): [[ -d /usr/lib/systemd ]]
    490 /usr/bin/dracut@1400(): [[ -d '' ]]
    491 //usr/bin/dracut@1401(): pkg-config systemd --variable=systemdutilconfdir
    492 /usr/bin/dracut@1401(): systemdutilconfdir=
    493 /usr/bin/dracut@1403(): [[ -d '' ]]
    494 /usr/bin/dracut@1403(): systemdutilconfdir=/etc/systemd
    495 /usr/bin/dracut@1405(): [[ '' != yes ]]

Fail Log:

    571 /usr/bin/dracut@1390(): outfile=/<pathToNewRoot>/boot/EFI/Linux/linux-6.5.0-dirty-x86_64-rolling_test.efi
    572 /usr/bin/dracut@1392(): [[ -d <pathToNewRoot> ]]
    573 /usr/bin/dracut@1395(): [[ -d <pathToNewRoot> ]]
    574 /usr/bin/dracut@1400(): [[ -d <pathToNewRoot> ]]
    575 /usr/bin/dracut@1403(): [[ -d <pathToNewRoot> ]]
    576 /usr/bin/dracut@1405(): [[ '' != yes ]]

So what I'm seeing for "success" is that dracut@1392 is NOT seeing a path (no $dracutsysrootdir or $systemdutildir) when --sysroot is NOT used, and pkg-config fills in $systemdutildir.
When --sysroot is used, only $dracutsysrootdir is set, and none of the subsequent checks folow-through to any pkg-config call.

I don't know if I'm supposed to be using the environment variables with --sysroot, since some of them say "Optional", but others say they are for sysroot, but don't specify "Optional", but I don't see the value of them like SYSTEMD_VERSION.
Are they required? What am I missing that the systemdutildir isn't being set?

EDIT0: I should probably state the reason why I'm pointing to systemdutildir is because of dracut: dracut module 'systemd' will not be installed, because command '/systemd' could not be found!.

EDIT1: Oh god! Is it due to dracut being out-of-date (that the needed stuff doesn't exist in a conf)?
I just saw https://github.com/dracutdevs/dracut/pull/2155/files, noticed the set_global_vars, noticed the date for that pull in relation to release-59 (which is what I'm on in Arch Linux).
Maybe it'd be nice to get a new release made since we're (sort of?) nearing 1 year since the last release?

EDIT2: Hmm, looking at dracut.conf man, I'm not seeing anything standing out that would apply to getting systemdutildir set.