REQUIRED dependencies are not installed, despite being installed (Debian 10.7)

[Perry Gibson]

Attempting to install HPLIP from the sourceforge page (https://developers.hp.com/hp-linux-imaging-and-printing/) v3.20.11.

My distribution is Debian 10.7. My printer is the support 2700 series.

The script fails at the dependency install stage.

```
MISSING DEPENDENCIES
--------------------
Following dependencies are not installed. HPLIP will not work if all REQUIRED dependencies are not installed and some of the HPLIP features will not work if OPTIONAL dependencies are not installed.
Package-Name Component Required/Optional
python3-notify2 gui_qt5 OPTIONAL
python3-pyqt4-dbus gui_qt4 OPTIONAL
python3-pyqt4 gui_qt4 REQUIRED
python3-pyqt5-dbus gui_qt5 OPTIONAL
python3-pyqt5 gui_qt5 REQUIRED
python3-dbus fax REQUIRED
python3-reportlab fax OPTIONAL
Do you want to install these missing dependencies (y=yes*, n=no, q=quit) ? y
```

However it fails with:

```
RE-CHECKING DEPENDENCIES
------------------------
error: A required dependency 'python3-pyqt4 (PyQt 4- Qt interface for Python (for Qt version 4.x))' is still missing.
error: A required dependency 'python3-pyqt5 (PyQt 5- Qt interface for Python (for Qt version 4.x))' is still missing.
error: A required dependency 'python3-dbus (Python DBus - Python bindings for DBus)' is still missing.
error: Installation cannot continue without these dependencies.
error: Please manually install this dependency and re-run this installer.
```

However, if I try and install the packages separately, I am told they are already installed:

```
$ sudo apt install python3-pyqt4 python3-pyqt5 python3-dbus
Reading package lists... Done
Building dependency tree
Reading state information... Done
python3-dbus is already the newest version (1.2.8-3).
python3-pyqt5 is already the newest version (5.11.3+dfsg-1+b3).
python3-pyqt4 is already the newest version (4.12.1+dfsg-2+b1).
```

Uninstalling them and re-running the installer causes the packages to be installed, however the `hplip-3.20.11.run` script still fails to recognise this.

[shivani mandora (shivani1708)]

Hi,

Debian 10.7 is not supported by HPLIP.
It will be supported in our next release. Please wait till then

[Perry Gibson (nmlck)]

Thanks, I note the new release has been pushed, cheers to the team.

I note however unfortunately Debian upgraded to 10.8 in the background in the interim.

Is there a planned the release cycle of HPLIP, so I can plan accordingly?