poudriere overlays build failed with xargs: illegal option -- e

[Miroslav Lachman]

I am trying to use port overlays with poudriere-devel.
I have main tree with old quaterly branch from December 2019 (default). 
The overlay contains just a bunch of ports from current tree with 
updated versions of Apache, Python etc. and Mk from current ports tree. 
This is called mfh_overlay.
I need this because I need to maintain some old SW not existing in 
current ports tree (phantomjs with old openssl for example)

Some ports are building fine but when port needs to be patched it is 
failing:

=>> Status   lang/python27 | python27-2.7.18: extract-depends
=======================<phase: extract-depends>============================
===========================================================================
=>> Status   lang/python27 | python27-2.7.18: extract
=======================<phase: extract        >============================
===>   NOTICE:

This port is deprecated; you may wish to reconsider installing it:

EOLed upstream.

It is scheduled to be removed on or after 2020-12-31.

===>   python27-2.7.18 depends on file: /usr/local/sbin/pkg - found
===> Fetching all distfiles required by python27-2.7.18 for building
===>  Extracting for python27-2.7.18
=> SHA256 Checksum OK for python/Python-2.7.18.tar.xz.
===========================================================================
=>> Status   lang/python27 | python27-2.7.18: patch-depends
=======================<phase: patch-depends  >============================
===========================================================================
=>> Status   lang/python27 | python27-2.7.18: patch
=======================<phase: patch          >============================
===>  Patching for python27-2.7.18
xargs: illegal option -- e
usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements] [-S 
replsize]]
              [-J replstr] [-L number] [-n number [-x]] [-P maxprocs]
              [-s size] [utility [argument ...]]
*** Error code 1

Stop.
make: stopped in /overlays/mfh_overlay/lang/python27
build of lang/python27 | python27-2.7.18 ended at Fri May 15 15:14:08 
CEST 2020
build time: 00:00:03
!!! build failure encountered !!!
[00:00:13] Error: Build failed in phase: patch
[00:00:13] Logs: 
/vol0/poudriere/data/logs/bulk/11_3_amd64-default-php71m103/2020-05-15_15h13m56s
[00:00:13] WWW: 
http://pkg.codelab.cz/build.html?mastername=11_3_amd64-default-php71m103&build=2020-05-15_15h13m56s
[00:00:13] Cleaning up


Does anybody know what is wrong with xargs and illegal option -e? I 
guess it is something in Mk but I don't know what is different in the 
current tree and the old one from December.
I did my last successfull build few weeks ago where the the ports trees 
were manually merged in to one. But is has some other problems so I am 
trying to use overlays.

Kind regards
Miroslav Lachman