Toaster is currently failing bitbaking with Hardknott and Honister releases

What do I do?
On a updated Debian 10 which was using Yocto some months ago successfully, checking out hardknott...

cd ~
mkdir yocto
cd yocto
git clone -b hardknott git://git.yoctoproject.org/poky.git
cd ~/yocto/poky
pip3 install --user -r bitbake/toaster-requirements.txt
cd ~/yocto/poky
source oe-init-build-env
source toaster start

Go into toaster, create a new project from Yocto Project master (both Hardknott and Honister are not available as options in their respective Yocto branches, only local and Master and older releases...), trying to build a "core-image-minimal" with all default settings does keep toaster hanging at "Tasks starting".

yocto/poky/build/toaster_runbuilds.log

2022-04-04 13:06:51,931 INFO runbuilds: starting build Project object (3) in progress, environment BuildEnvironment object (1)
2022-04-04 13:06:51,933 DEBUG localhostbecontroller, our git repos are {('git://git.yoctoproject.org/poky', 'master'): [('bitbake', 'bitbake', 0),
('openembedded-core',
'meta',
0),
('meta-poky', 'meta-poky', 1),
('meta-yocto-bsp',
'meta-yocto-bsp',
2)]}
2022-04-04 13:06:51,933 DEBUG lbc_shellcmd: (/home/user/yocto/poky) git remote -v
2022-04-04 13:06:51,936 DEBUG localhostbecontroller: shellcmd success
2022-04-04 13:06:51,936 INFO Using pre-checked out source for layer {'git://git.yoctoproject.org/poky.git': '/home/user/yocto/poky'}
2022-04-04 13:06:51,939 DEBUG localhostbecontroller: giturl git://git.yoctoproject.org/poky:master checking out in current directory /home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master
2022-04-04 13:06:51,939 DEBUG lbc_shellcmd: (/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master) git remote -v
2022-04-04 13:06:51,941 DEBUG localhostbecontroller: shellcmd success
2022-04-04 13:06:51,942 DEBUG localhostbecontroller: checking out commit master to /home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master
2022-04-04 13:06:51,942 DEBUG lbc_shellcmd: (/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master) git fetch && git reset --hard "origin/master"
2022-04-04 13:06:52,965 DEBUG localhostbecontroller: shellcmd success
2022-04-04 13:06:52,965 DEBUG localhostbecontroller: selected poky dir name /home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master
2022-04-04 13:06:52,965 DEBUG localhostbecontroller: localdirpath expects '/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake'
2022-04-04 13:06:52,965 DEBUG localhostbecontroller: localdirpath expects '/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta'
2022-04-04 13:06:52,965 DEBUG localhostbecontroller: localdirpath expects '/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta-poky'
2022-04-04 13:06:52,965 DEBUG localhostbecontroller: localdirpath expects '/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta-yocto-bsp'
2022-04-04 13:06:52,966 DEBUG localhostbecontroller: current layer list ['000:/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta',
'001:/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta-poky',
'002:/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta-yocto-bsp']
2022-04-04 13:06:52,968 DEBUG

set layers gives this list ['000:/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta',
'001:/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta-poky',
'002:/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/meta-yocto-bsp']
2022-04-04 13:06:52,968 DEBUG lbc_shellcmd: (/home/user/yocto/poky) bash -c 'source /home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/oe-init-build-env /home/user/yocto/poky/build-toaster-3'
2022-04-04 13:06:53,004 DEBUG localhostbecontroller: shellcmd success
2022-04-04 13:06:53,005 DEBUG lbc_shellcmd: (/home/user/yocto/poky) unset BBPATH; bash -c "source /home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/oe-init-build-env /home/user/yocto/poky/build-toaster-3; BITBAKE_UI="knotty" /home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/bin/bitbake --read /home/user/yocto/poky/build-toaster-3/conf/toaster.conf --read /home/user/yocto/poky/build-toaster-3/conf/toaster-bblayers.conf --server-only -B 0.0.0.0:0"
2022-04-04 13:06:53,452 DEBUG localhostbecontroller: shellcmd success
2022-04-04 13:06:53,453 DEBUG localhostbecontroller: bitbake port 38709
2022-04-04 13:06:53,454 DEBUG lbc_shellcmd: (/home/user/yocto/poky/build-toaster-3) ['unset BBPATH; bash -c "(TOASTER_BRBE="3:1" BBSERVER="0.0.0.0:38709" /home/user/yocto/poky/bitbake/bin/bitbake core-image-minimal  -u toasterui  --read /home/user/yocto/poky/build-toaster-3/conf/toaster.conf --read /home/user/yocto/poky/build-toaster-3/conf/toaster-bblayers.conf --token="" >>/home/user/yocto/poky/build-toaster-3/toaster_ui.log 2>&1;BITBAKE_UI="knotty" BBSERVER=0.0.0.0:38709 /home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/bin/bitbake -m)&"']
2022-04-04 13:06:53,456 DEBUG localhostbecontroller: Build launched, exiting. Follow build logs at /home/user/yocto/poky/build-toaster-3/toaster_ui.log

yocto/poky/build-toaster-3/toaster_ui.log

Traceback (most recent call last):
File "/home/user/yocto/poky/bitbake/bin/bitbake", line 36, in <module>
cookerdata.CookerConfiguration()))
File "/home/user/yocto/poky/bitbake/lib/bb/main.py", line 386, in bitbake_main
configParams)
File "/home/user/yocto/poky/bitbake/lib/bb/ui/toasterui.py", line 135, in main
params.updateToServer(server, os.environ.copy())
File "/home/user/yocto/poky/bitbake/lib/bb/cookerdata.py", line 75, in updateToServer
raise Exception("Unable to update the server configuration with local parameters: %s" % error)
Exception: Unable to update the server configuration with local parameters: bb.BBHandledException()
Traceback (most recent call last):
File "/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/lib/bb/command.py", line 90, in runCommand
result = command_method(self, commandline)
File "/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/lib/bb/command.py", line 286, in updateConfig
command.cooker.updateConfigOpts(options, environment, cmdline)
File "/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/lib/bb/cooker.py", line 536, in updateConfigOpts
self.reset()
File "/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/lib/bb/cooker.py", line 1776, in reset
self.initConfigurationData()
File "/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/lib/bb/cooker.py", line 389, in initConfigurationData
self.databuilder = bb.cookerdata.CookerDataBuilder(self.configuration, False)
File "/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/lib/bb/cookerdata.py", line 252, in __init__
bb.fatal("Exiting to allow enviroment variables to be corrected")
File "/home/user/yocto/poky/_toaster_clones/_git___git.yoctoproject.org_poky_master/bitbake/lib/bb/__init__.py", line 178, in fatal
raise BBHandledException()
bb.BBHandledException

This happens with both Honister and Hardknott, Gatesgarth and Dunfell are working fine.
How to resolve this issue?

Thanks a lot!

Nico