multiple versions of gnome-shell simultaneously: setting up a handy dev environment for extension testing

[Amy C <mathematical coffee gmail com>]

Hi all,

I have briefly toyed with building gnome-shell from source before
(although I have never yet had it succeed - but that is for another
day when I try it properly).

Does anyone have experience with having multiple versions of
gnome-shell on the one computer simultaneously and switching between
them?

It's just that two of my computers have gnome 3.4 and one has gnome
3.2, and when I develop extensions I like to test them in both, which
involves shuttling the files between computers all the time (and when
3.5 comes out in Ubuntu ??.?? I'll put one computer on that too).

It'd be handier if I just had multiple versions of gnome-shell
installed on my main computer and I can just do (say) 'gnome-shell
--version 3.2 --replace' to boot up v3.2 for testing, and then
'gnome-shell --version 3.4 --replace' to switch to 3.4 and test there.

Is such a thing possible? What do you guys do to handle testing on
different versions of gnome shell?

thanks!