dpm@el-far:~/term-build$ LC_ALL=C pkcon install-local dekko.dekkoproject_0.5.4_amd64.click --allow-untrusted
Installing files              [=========================]         
Loading cache                 [=========================]         
Resolving dependencies        [=========================]         
Finished                      [=========================]         
Installing files              [=========================]         
Loading cache                 [=========================]         
Resolving dependencies        [=========================]         
Waiting for authentication    [=========================]   

# Note: here ^^ I'm being presented with a graphical prompt
# to enter my password. This is the step that fails on the
# container. However, it's strange that I'm being asked for
# it, as when running this command on the phone I'm not
# being prompted for it.
      
Loading cache                 [=========================]         
Resolving dependencies        [=========================]         
Committing changes            [=========================]         
Finished                      [=========================]         
(Reading database ... 409802 files and directories currently installed.)
Preparing to unpack .../dekko.dekkoproject_0.5.4_amd64.click ...
Click packages may not be installed directly using dpkg.
Use 'click install' instead.
dpkg: error processing archive /home/dpm/term-build/dekko.dekkoproject_0.5.4_amd64.click (--install):
 subprocess new pre-installation script returned error exit status 1
Errors were encountered while processing:
 /home/dpm/term-build/dekko.dekkoproject_0.5.4_amd64.click