Mail does not show the main window

[L. Vales]

Since a few weeks ago, I have not been able to properly launch pantheon-mail. The main window is not drawn correctly, and it appears like in the screenshot I've attached

Here's what I have been able to find:
- The background processes are still running fine, because if I leave the application running, I'll eventually get the notification that I have X new e-mails on Y account; so, it's just the drawing of the main window that's borked.
- This does not seem like a regression introduced by a new revision, because I had a compiled package for r1977 lying around, and if I downgrade the package, the same kind of behaviour still occurs.
- There's nothing wrong with the accounts configuration themselves - not only does pantheon-mail still successfully synchronizes with the e-mail servers (as described above), but deleting ~/.local/share/pantheon-mail, starting the application and adding an account (regardless of whether it's a gmail or another mail server) still shows the same behaviour.
- Running with --debug switch does not seem to throw any error helpful (at least for me). Still, I've attached the output of said command.
- When pantheon-mail is running, it makes the system sluggish. Changing apps (alt-tab), trying to use pantheon-terminal, etc, and everything acts as if the computer was under heavy load (slow and delay animations, slow input, etc).

Now, since I'm running Arch, I'd assume that this is either a package upgrade that broke something. I've been trying to downgrade packages (viz., gtk3, sqlite, and mutter), and recompiling, but this does not seem to help. Maybe it's a combination of packages, or some other package that I have not yet tested (maybe gala? or even the intel video driver). In any case, all my pantheon packages are (I believe) up-to-date to the bzr revisions.

If there's any more info I can give, please do tell.
Best.

----

$ ~ pantheon-mail --debug

(pantheon-mail:30447): GLib-WARNING **: g_set_application_name() called multiple times
 [msg] 13:49:24 0.068556 geary-application.vala:197: Mail 0.10.0 prefix=/usr exec_dir=/usr/bin is_installed=true
 [deb] 13:49:24 0.172453 null-indicator.vala:13: No messaging menu support in this build
 [deb] 13:49:24 0.019017 imap-client-session-manager.vala:525: Checking if IMAP host imap.gmail.com/default:993 reachable...
 [msg] 13:49:25 0.217160 imap-client-session-manager.vala:536: IMAP host imap.gmail.com/default:993 considered reachable
 [deb] 13:49:25 0.184341 db-versioned-database.vala:77: VersionedDatabase.upgrade: current database schema for /<email address hidden>/geary.db: 24
 [deb] 13:49:25 0.002310 imap-db-gc.vala:105: [GC:/<email address hidden>/geary.db] GC state: last_reap_time=2016-03-14T10:40:05+0000 last_vacuum_time=never reaped_messages_since=0 free_page_bytes=225280
 [deb] 13:49:25 0.000074 imap-db-gc.vala:128: [GC:/<email address hidden>/geary.db] Reaping last completed on 2016-03-14T10:40:05+0000 (0 days ago)
 [deb] 13:49:25 0.000007 imap-db-gc.vala:138: [GC:/<email address hidden>/geary.db] Database never vacuumed (0 messages reaped)
 [deb] 13:49:25 0.005814 smtp-outbox-folder.vala:139: Starting outbox postman

(pantheon-mail:30447): Gtk-CRITICAL **: gtk_widget_get_allocated_height: assertion 'GTK_IS_WIDGET (widget)' failed

(pantheon-mail:30447): Gtk-CRITICAL **: gtk_widget_get_allocated_height: assertion 'GTK_IS_WIDGET (widget)' failed

(pantheon-mail:30447): Gtk-CRITICAL **: gtk_widget_get_allocated_height: assertion 'GTK_IS_WIDGET (widget)' failed

(pantheon-mail:30447): Gtk-CRITICAL **: gtk_widget_get_allocated_height: assertion 'GTK_IS_WIDGET (widget)' failed

(pantheon-mail:30447): Gtk-CRITICAL **: gtk_widget_get_allocated_height: assertion 'GTK_IS_WIDGET (widget)' failed