I am affected by this issue as well. Started occurring after this upgrade in testing:
======================================== [REMOVE, NOT USED] gir1.2-gdm3:amd64 3.18.0-2 [REMOVE, NOT USED] libical1a:amd64 1.0.1-0.1 [REMOVE, NOT USED] libmutter0g:amd64 3.18.3-2 [INSTALL, DEPENDENCIES] gir1.2-gdm-1.0:amd64 3.20.1-1 [INSTALL, DEPENDENCIES] libmutter0h:amd64 3.20.2-1 [UPGRADE] gdm3:amd64 3.18.0-2 -> 3.20.1-1 [UPGRADE] gir1.2-gdesktopenums-3.0:amd64 3.18.1-1 -> 3.20.0-3 [UPGRADE] gir1.2-javascriptcoregtk-3.0:amd64 2.4.11-1 -> 2.4.11-1+b1 [UPGRADE] gir1.2-mutter-3.0:amd64 3.18.3-2 -> 3.20.2-1 [UPGRADE] gir1.2-webkit-3.0:amd64 2.4.11-1 -> 2.4.11-1+b1 [UPGRADE] gnome-control-center:amd64 1:3.18.2-1 -> 1:3.20.1-1 [UPGRADE] gnome-control-center-data:amd64 1:3.18.2-1 -> 1:3.20.1-1 [UPGRADE] gnome-keyring:amd64 3.18.3-1 -> 3.20.0-1 [UPGRADE] gnome-session:amd64 3.18.1.2-1 -> 3.20.1-2 [UPGRADE] gnome-session-bin:amd64 3.18.1.2-1 -> 3.20.1-2 [UPGRADE] gnome-session-common:amd64 3.18.1.2-1 -> 3.20.1-2 [UPGRADE] gnome-settings-daemon:amd64 3.18.2-1 -> 3.20.1-1 [UPGRADE] gnome-shell:amd64 3.18.1-1 -> 3.20.2-1 [UPGRADE] gnome-shell-common:amd64 3.18.1-1 -> 3.20.2-1 [UPGRADE] gnome-shell-extensions:amd64 3.18.4-1 -> 3.20.1-1 [UPGRADE] gnome-themes-standard:amd64 3.20-1 -> 3.20.2-1 [UPGRADE] gnome-themes-standard-data:amd64 3.20-1 -> 3.20.2-1 [UPGRADE] gsettings-desktop-schemas:amd64 3.18.1-1 -> 3.20.0-3 [UPGRADE] libbluray1:amd64 1:0.9.2-2 -> 1:0.9.3-2 [UPGRADE] libetonyek-0.1-1:amd64 0.1.6-1 -> 0.1.6-2 [UPGRADE] libgdm1:amd64 3.18.0-2 -> 3.20.1-1 [UPGRADE] libjavascriptcoregtk-3.0-0:amd64 2.4.11-1 -> 2.4.11-1+b1 [UPGRADE] libpam-gnome-keyring:amd64 3.18.3-1 -> 3.20.0-1 [UPGRADE] libselinux1:amd64 2.5-2 -> 2.5-3 [UPGRADE] libselinux1:i386 2.5-2 -> 2.5-3 [UPGRADE] libselinux1-dev:amd64 2.5-2 -> 2.5-3 [UPGRADE] libwebkitgtk-3.0-0:amd64 2.4.11-1 -> 2.4.11-1+b1 [UPGRADE] mutter:amd64 3.18.3-2 -> 3.20.2-1 [UPGRADE] mutter-common:amd64 3.18.3-2 -> 3.20.2-1 [UPGRADE] python-pyparsing:amd64 2.1.1+dfsg1-1 -> 2.1.4+dfsg1-1 [UPGRADE] sgml-base:amd64 1.26+nmu4 -> 1.27 [UPGRADE] tar:amd64 1.28-2.2 -> 1.29-1 ======================================== Found this bug which seems to be related: https://bbs.archlinux.org/viewtopic.php?id=211100
