Situation without the patch 

root 00:01 : /usr/lib/tmpfiles.d # systemctl status systemd-tmpfiles-setup.service
* systemd-tmpfiles-setup.service - Create Volatile Files and Directories
     Loaded: loaded (/usr/lib/systemd/system/systemd-tmpfiles-setup.service; st>
     Active: active (exited) since Tue 2020-09-01 00:00:12 UTC; 1min 39s ago
       Docs: man:tmpfiles.d(5)
             man:systemd-tmpfiles(8)
    Process: 139 ExecStart=/usr/bin/systemd-tmpfiles --create --remove --boot ->
   Main PID: 139 (code=exited, status=73)
        CPU: 343ms

Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Failed to open directory 'spool': >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[139]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd[1]: Finished systemd-tmpfiles-setup.service.


Now with the patched systemd.in in project/rules -> menuconfig

diff --git a/ptxdist/configs/ecu02/ptxconfig b/ptxdist/configs/ecu02/ptxconfig
index 2422a2563..130cfbd90 100644
--- a/ptxdist/configs/ecu02/ptxconfig
+++ b/ptxdist/configs/ecu02/ptxconfig
@@ -96,7 +96,6 @@ PTXCONF_HOST_EXPAT=y
 PTXCONF_HOST_FIGLET=y
 PTXCONF_HOST_FILE=y
 PTXCONF_HOST_FLEX=y
-PTXCONF_HOST_GETTEXT=y
 PTXCONF_HOST_GLIB=y
 PTXCONF_HOST_GPERF=y
 PTXCONF_HOST_LIBARCHIVE=y
@@ -222,7 +221,7 @@ PTXCONF_ROOTFS_VAR_LOG=y
 PTXCONF_ROOTFS_VAR_LOCK=y
 PTXCONF_ROOTFS_VAR_LIB=y
 PTXCONF_ROOTFS_VAR_CACHE=y
-# PTXCONF_ROOTFS_VAR_SPOOL is not set
+PTXCONF_ROOTFS_VAR_SPOOL=y
 # PTXCONF_ROOTFS_VAR_SPOOL_CRON is not set
 PTXCONF_ROOTFS_VAR_TMP=y


Now build again and reboot DUT

[schenk:~/projects/jcng/ptxdist] master(+1/-2)* 3m29s ± cd platform-ecu02/root/var/
l[schenk:~/projects/jcng/ptxdist/platform-ecu02/root/var] master(+1/-2)* ± ls
cache  dyn  lib  lock  log  run  spool  stat  tmp


root 00:00 : ~ # systemctl status systemd-tmpfiles-setup.service
* systemd-tmpfiles-setup.service - Create Volatile Files and Directories
     Loaded: loaded (/usr/lib/systemd/system/systemd-tmpfiles-setup.service; st>
     Active: active (exited) since Tue 2020-09-01 00:00:12 UTC; 39s ago
       Docs: man:tmpfiles.d(5)
             man:systemd-tmpfiles(8)
    Process: 138 ExecStart=/usr/bin/systemd-tmpfiles --create --remove --boot ->
   Main PID: 138 (code=exited, status=73)
        CPU: 356ms

Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd-tmpfiles[138]: Detected unsafe path transition / >
Sep 01 00:00:12 ecu02 systemd[1]: Finished systemd-tmpfiles-setup.service.