Problem with gnome-shell-extension-prefs on GNOME 3.4.2

[Amy C <mathematical coffee gmail com>]

Hi all,

I have a user who has reported that one of my extensions (along with
one other) work fine, but will crash the prefs widget on GNOME 3.4.2.

Symptoms:
- extension seems to work fine
- go to terminal, type gnome-shell-extension-prefs
- the prefs widget opens fine.
- selecting other extensions loads their prefs widgets
- selecting mine or the other extension causes the dialog to close

Log in the terminal:

~> gnome-shell-extension-prefs
Warning: Missing "url" property in metadata.json
Warning: Missing "url" property in metadata.json
/usr/bin/gnome-shell-extension-prefs: line 15:  7143 Segmentation
fault      /usr/bin/gjs-console -I /usr/share/gnome-shell/js -c "const
Main = imports.extensionPrefs.main; Main.main(ARGV);" "$@"


Does anyone know what this could be? I cannot reproduce on GNOME
3.4.1. Or can anyone else on 3.4.2 verify this? Installed from e.g.o.

The two extensions that they can get this behaviour with are:
* Status area horizontal spacing (mine - a very simple prefs widget,
consisting of a single slider)
* Dash to dock (michele_g)

The user has re-compiled all the schemas just in case I somehow
accidentally shipped an out-of-date schema with the extension.

I am waiting on the result of 'gdb gnome-shell-extension-prefs; run
status-area-horizontal-spacing mathematical coffee gmail com' to see
if it gives any further info (are there other debugging steps I could
ask the user to do?)

cheers.