Uninstallable build-deps

$ sudo apt-get build-dep ./
sudo: setrlimit(RLIMIT_CORE): Operation not permitted
Note, using directory './' to get the build dependencies
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 builddeps:./ : Depends: python-sphinx but it is not going to be installed
                Depends: doxygen-latex but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Chasing it down a bit:

 doxygen-latex : Depends: texlive-latex-extra but it is not going to be installed
 python-sphinx : Depends: python-docutils but it is not going to be installed
                 Depends: python-packaging but it is not going to be installed

 python-docutils : Depends: python:any (< 2.8)
                   Depends: python:any (>= 2.7~)
 python-packaging : Depends: python:any (< 2.8)
                    Depends: python:any (>= 2.7~)

 texlive-latex-extra : Depends: texlive-pictures (>= 2019.20191112) but it is not going to be installed

 texlive-pictures : Depends: python but it is not going to be installed