The instructions that Blubber generates for installing python packages no longer work on Bookworm. For example:
```
RUN python3 "-m" "pip" "install" "-U" "setuptools!=60.9.0" && python3 "-m" "pip" "install" "-U" "wheel" "tox" "pip"
#12 1.446 error: externally-managed-environment
#12 1.446
#12 1.446 × This environment is externally managed
#12 1.446 ╰─> To install Python packages system-wide, try apt install
#12 1.446 python3-xyz, where xyz is the package you are trying to
#12 1.446 install.
#12 1.446
#12 1.446 If you wish to install a non-Debian-packaged Python package,
#12 1.446 create a virtual environment using python3 -m venv path/to/venv.
#12 1.446 Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
#12 1.446 sure you have python3-full installed.
#12 1.446
#12 1.446 If you wish to install a non-Debian packaged Python application,
#12 1.446 it may be easiest to use pipx install xyz, which will manage a
#12 1.446 virtual environment for you. Make sure you have pipx installed.
#12 1.446
#12 1.446 See /usr/share/doc/python3.11/README.venv for more information.
#12 1.446
#12 1.446 note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
#12 1.446 hint: See PEP 668 for the detailed specification.
```
As stated in the error message, there are two options for working around this:
[] Pass `--break-system-packages` to `pip` (but only if needed). This is the easiest approach but leaves the risk in place.
[] Use a virtualenv as the holding place for packages.