I can share a bit my experience with tonel and Pharo. I have been using
Tonel on Pharo now for DrGeo code. However I don't use git for several
reasons, I use Launchpad/Bazzar. So it will be a bit the same situation
as Squeak with Tonel content commited to GIT repo.

So all in all from the image I don't have access to versioning, I have
to do it externally from the bzr line command or Launchpad web
interface[1] and it is pretty nice. So it is not very different when
developing with other system.

This is so far an acceptable trade-off, but I am so far only one
developer on this repository.

Hilaire

[1]
https://bazaar.launchpad.net/~drgeo-developers/drgeo/trunk/files/head:/src/

Le 15/02/2019 à 02:14, David T. Lewis a écrit :
> I am a big fan of git, but I do not care about integrating it with the
> image (Squeak/Pharo) because I prefer using the in-image tools in Squeak,
> and when I do use git, I prefer to use git tools directly.
>
> I am not well informed about this topic, but overall I would say that being
> able to read and write Tonel format from Squeak would be very helpful, and
> I would probably not care very much about version control integration.

-- 
Dr. Geo
http://drgeo.eu