CHIRP

I had the same error while attempting to install on a 32-bit instance of Ubuntu-Mate (18.04). It installed and runs on 64-bit version; actually it was Ubuntu-mate 20.04. I also have Chirp installed on a persistent USB with Ubuntu-Mint (19.3), using these instructions:

https://oneguyoneblog.com/2018/01/31/chirp-pofung-baofeng-uv-5r-linux-windows/

sudo apt-add-repository ppa:dansmith/chirp-snapshots
sudo apt-get update
sudo apt-get install chirp-daily

, but I think it installed an earlier version.

I should have mentioned that the persistent USB was also 32-bit (Linux Mint 19.3 "Tricia" - Cinnamon (32-bit)).

https://linuxmint.com/edition.php?id=273

Using a test box, I did a lot of experimenting and was able to get around the error (mostly). Did the following:

sudo apt-add-repository ppa:dansmith/chirp-snapshots
sudo apt-get update
sudo apt-get install chirp-daily

sudo add-apt-repository ppa:alexlarsson/flatpak
sudo apt update
sudo apt install flatpak

flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
flatpak install org.freedesktop.Platform/x86_64/19.08

Downloaded the latest Chirp from danplanet.com

cd /home/don/Downloads
flatpak install chirp-daily-20201221.flatpak

Notes of interest:
1-Installing with flatpak works much better on a 64-bit box than a 32-bit box.
2-On a 32-bit box, installing with flatpak directly (not using apt-get) , sometimes the menu launcher did not appear; if it did appear, it did not work (clicking on it didn't do anything). Running the apt-get commands solved the problem.
3-Installing x86_64/19.08 had an error with "org.freedesktop.Platform.openh264" that can be ignored. Apparently, it's a known flatpak issue that's been solved in the 64-bit environment, but not on 32-bit.
4-I thought I was installing the latest version of Chirp (20201221), but "About" reports it's version as "20201121". When launching, it recommends that I update the program. I'll mention this on the mailing list.

OK with me, with some effort, I was able to successfully install it. Not sure about others.

Looks like the underlying cause here is that PyGtk is no longer supported under many debian/ubuntu flavours because it is python2 only and GTK2 only. Ubuntu repos have pulled support for pyton2 since 20.04LTS which came out April 2020.

That is the 800lbs gorilla moving away... so really it might be time for this:

https://pygobject.readthedocs.io/en/latest/guide/porting.html

ie, migrating the code to the new pygobject which is GTK3.

It doesn't look too hard based on that page with some script based auto-migration to do the tedious lifting

I would be happy to help if you are manpower constrained. Let me know.