GSettings schemas

[Ludovic Courtès]

Federico Beffa <address@hidden> skribis:

> (emacs:33176): GLib-GIO-ERROR **: attempting to create schema 
> 'org.gtk.Settings.FileChooser' without a path
>
> Program received signal SIGTRAP, Trace/breakpoint trap.
> 0x00007ffff4dfd0ba in g_logv () from 
> /gnu/store/7v44p77l3867slbpnamzs5jgbyps2v7q-glib-2.40.0/lib/libglib-2.0.so.0
> (gdb) bt
> #0  0x00007ffff4dfd0ba in g_logv () from 
> /gnu/store/7v44p77l3867slbpnamzs5jgbyps2v7q-glib-2.40.0/lib/libglib-2.0.so.0
> #1  0x00007ffff4dfd212 in g_log () from 
> /gnu/store/7v44p77l3867slbpnamzs5jgbyps2v7q-glib-2.40.0/lib/libglib-2.0.so.0
> #2  0x00007ffff5f6af54 in g_settings_constructed () from 
> /gnu/store/7v44p77l3867slbpnamzs5jgbyps2v7q-glib-2.40.0/lib/libgio-2.0.so.0
> #3  0x00007ffff50f433a in g_object_new_internal () from 
> /gnu/store/7v44p77l3867slbpnamzs5jgbyps2v7q-glib-2.40.0/lib/libgobject-2.0.so.0
> #4  0x00007ffff50f6444 in g_object_new_valist () from 
> /gnu/store/7v44p77l3867slbpnamzs5jgbyps2v7q-glib-2.40.0/lib/libgobject-2.0.so.0
> #5  0x00007ffff50f6834 in g_object_new () from 
> /gnu/store/7v44p77l3867slbpnamzs5jgbyps2v7q-glib-2.40.0/lib/libgobject-2.0.so.0
> #6  0x00007ffff6830e9c in _gtk_file_chooser_get_settings_for_widget () from 
> /gnu/store/5shj344c9vrh4fx93r9lfjjrrr97fmjv-gtk+-3.10.1/lib/libgtk-3.so.0
> #7  0x00007ffff6828130 in gtk_file_chooser_default_get_default_size () from 
> /gnu/store/5shj344c9vrh4fx93r9lfjjrrr97fmjv-gtk+-3.10.1/lib/libgtk-3.so.0
> #8  0x00007ffff682eda4 in file_chooser_widget_default_size_changed () from 
> /gnu/store/5shj344c9vrh4fx93r9lfjjrrr97fmjv-gtk+-3.10.1/lib/libgtk-3.so.0

[...]

> #24 0x00000000004cc010 in xg_get_file_with_chooser ()
> #25 0x00000000004d00ea in xg_get_file_name ()
> #26 0x00000000004bd3f9 in Fx_file_dialog ()

I see, I can reproduce it by clicking on the “open file” icon.

> I've found that setting the environment variable GSETTINGS_SCHEMA_DIR
> solves the problem.
>
> $ 
> GSETTINGS_SCHEMA_DIR=/gnu/store/5shj344c9vrh4fx93r9lfjjrrr97fmjv-gtk+-3.10.1/share/glib-2.0/schemas
>  emacs
>
> Can the schema location be fixed at configure/compile time?

We could use ‘wrap-program’ to set that variable for Emacs, but we need
to address that problem more generally.

This is actually a longstanding issue:
http://lists.gnu.org/archive/html/guix-devel/2013-10/msg00171.html
http://lists.gnu.org/archive/html/guix-devel/2013-10/msg00024.html
http://lists.gnu.org/archive/html/guix-devel/2013-11/msg00019.html

I would introduce a ‘glib-build-system’ that would have a post-install
phase to recompile the schemas visible to the package being built, and
wrap the binaries so GSETTINGS_SCHEMA_DIR refers to them.

I think that makes for a good project for this week-end’s hackathon.
Any volunteer?  :-)

Thanks,
Ludo’.