TypeError: 'NoneType' object is not callable while building from source

Following instructions to [install from source](https://guake.readthedocs.io/en/latest/user/installing.html#install-from-source) on an Ubuntu 20.04 (used `./scripts/bootstrap-dev-debian.sh`).

```
$ sudo make install
install -dm755 "//usr/local/share/applications"
install -Dm644 "/home/user/foo/guake/guake/data/guake.desktop" "//usr/local/share/applications/"
install -Dm644 "/home/user/foo/guake/guake/data/guake-prefs.desktop" "//usr/local/share/applications/"
install -dm755 "//usr/local/share/metainfo/"
install -Dm644 "/home/user/foo/guake/guake/data/guake.desktop.metainfo.xml" "//usr/local/share/metainfo/"
install -dm755 "//usr/local/share/guake/pixmaps"
install -Dm644 "/home/user/foo/guake/guake/data"/pixmaps/*.png "//usr/local/share/guake/pixmaps/"
install -Dm644 "/home/user/foo/guake/guake/data"/pixmaps/*.svg "//usr/local/share/guake/pixmaps/"
install -dm755 "//usr/local/share/pixmaps"
install -Dm644 "/home/user/foo/guake/guake/data/pixmaps/guake.png" "//usr/local/share/pixmaps/"
install -dm755 "//usr/local/share/guake"
install -Dm644 "/home/user/foo/guake/guake/data/autostart-guake.desktop" "//usr/local/share/guake/"
install -dm755 "//usr/local/share/guake"
install -Dm644 "/home/user/foo/guake/guake/data"/*.glade "//usr/local/share/guake/"
install -dm755 "//usr/local/share/glib-2.0/schemas"
install -Dm644 "/home/user/foo/guake/guake/data/org.guake.gschema.xml" "//usr/local/share/glib-2.0/schemas/"
if [ 1 = 1 ]; then glib-compile-schemas //usr/local/share/glib-2.0/schemas; fi
for f in $(find po -iname "*.mo"); do \
l="${f%%.*}"; \
lb=$(basename $l); \
install -Dm644 "$f" "//usr/local/share/locale/$lb/LC_MESSAGES/guake.mo"; \
done;
# you probably want to execute this target with sudo:
# sudo make install
#############################################################

Installing from source on your system is not recommended.
Please prefer you application package manager (apt, yum, ...)

#############################################################
Traceback (most recent call last):
File "setup.py", line 5, in
setuptools.setup(
File "/usr/lib/python3/dist-packages/setuptools/__init__.py", line 144, in setup
return distutils.core.setup(**attrs)
File "/usr/lib/python3.8/distutils/core.py", line 108, in setup
_setup_distribution = dist = klass(attrs)
File "/usr/lib/python3/dist-packages/setuptools/dist.py", line 447, in __init__
_Distribution.__init__(self, {
File "/usr/lib/python3.8/distutils/dist.py", line 292, in __init__
self.finalize_options()
File "/usr/lib/python3/dist-packages/setuptools/dist.py", line 740, in finalize_options
ep.load()(self)
File "/usr/lib/python3/dist-packages/setuptools/dist.py", line 747, in _finalize_setup_keywords
ep.load()(self, ep.name, value)
File "/usr/lib/python3/dist-packages/setuptools_scm/integration.py", line 17, in version_keyword
dist.metadata.version = _get_version(config)
File "/usr/lib/python3/dist-packages/setuptools_scm/__init__.py", line 150, in _get_version
version_string = format_version(
File "/usr/lib/python3/dist-packages/setuptools_scm/version.py", line 307, in format_version
local_version = local_scheme(version)
TypeError: 'NoneType' object is not callable
make: *** [Makefile:93: install-guake] Error 1
```