Advice on installing Gnucash on PureOS

New Librem 13v3 user here. Recently completed a traumatic migration of Thunderbird email archives and address books from Windows (and old message folder backups back to 2001) and currently working on printers, Firefox and Gnucash.

With regard to Gnucash, I have v2.6.16 on Windows 8.1 that I would like to migrate to PureOS soon. Given the trauma of email message and address book migration, I’ve steeled myself for another ordeal. I would like to install 2.6.16 or the more recent 2.6.19 on my Librem in the least complicated manner avoiding creating a PureOS Frankenstein monster. This would also apply to Firefox, which I would prefer over PureBrowser because I can use Cliqz or Ublock Origin to remove ads.

I’ve been reading posts and web pages for a week and am pretty thoroughly confused. I’d like to install a repo, but I don’t want side-effects from the many other apps that (may) conflict with the PureOS distro (Debian Testing, buster). Is there a debian testing compatible repo that includes only Gnucash, or that includes Gnucash and is safe for PureOS?

If a repo is not the right way to go, should I download a .deb package and install it standalone?

If Gnucash is imminent on PureOS, should I just keep using Windows until it shows up in my standard repo?

I am also interested in these answers as applied to Firefox.

See my post Gnucash cannot be installed

Thank you for your reference. I didn’t read that post because of the title.

I am flabbergasted (gobsmacked) at how easily that worked. Thank you for the detailed output and guidance, but all I did was say “yes” to everything and it all just worked. Even the app icon showed up in Show Applications.

Did you find a way to install aqbanking?

I ended up installing gnucash from stretch repository, but even though aqbanking comes with, I could not get it to work. I switched to kMyMoney instead and online banking worked perfectly after finding the right BoA entry and I think I like it better. So kMyMoney (and the uBlock Origin extension) and I’m finally happy with my setup. Almost vanilla, which suits me well.