I have several snap apps running nicely in Ubuntu 20.04 (using the default Gnome Desktop). However, on a TigerVNC-Server on that PC (that uses XFCE4), most of the snap apps don't even launch. According to the error messages, at least one problem seems to be the connection to the VNC-server display (:37 for my server). Does anyone have suggestions how to make snaps work on the VNC display?
Here some information:
The VNC server is startet using vncserver -localhost no :37
Snaps installed are:
$ snap list
Name Version Rev Tracking Publisher Notes
cherrytree 0.99.36 40 latest/stable hellsworth -
chromium 91.0.4472.106 1637 latest/stable canonical✓ -
core 16-2.51 11187 latest/stable canonical✓ core
core18 20210507 2066 latest/stable canonical✓ base
eclipse 2019-12 48 latest/stable snapcrafters classic
gnome-3-28-1804 3.28.0-19-g98f9e67.98f9e67 145 latest/stable canonical✓ -
gnome-3-34-1804 0+git.3556cb3 72 latest/stable/… canonical✓ -
gtk-common-themes 0.1-52-gb92ac40 1515 latest/stable/… canonical✓ -
gtk2-common-themes 0.1 13 latest/stable canonical✓ -
jabref 5.2.60000 1021 latest/stable koppor -
keepassxc 2.6.6 1522 latest/stable keepassxreboot -
pdftk 2.02-4 9 latest/stable smoser -
snap-store 3.38.0-64-g23c4c77 547 latest/stable/… canonical✓ -
snapd 2.51 12159 latest/stable canonical✓ snapd
pdftk, chromium and eclipse work, so it doesn't seem to be a general problem with snaps. However, I got the following errors for other snaps which run without any problem on the host system.
$ keepassxc
No protocol specified
qt.qpa.screen: QXcbConnection: Could not connect to display :37.0
Could not connect to any X display.
$ jabref
Picked up _JAVA_OPTIONS: -Duser.home=/home/ludwig/snap/jabref/1021
ERROR StatusLogger Unrecognized format specifier [d]
ERROR StatusLogger Unrecognized conversion specifier [d] starting at position 16 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [thread]
ERROR StatusLogger Unrecognized conversion specifier [thread] starting at position 25 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [level]
ERROR StatusLogger Unrecognized conversion specifier [level] starting at position 35 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [logger]
ERROR StatusLogger Unrecognized conversion specifier [logger] starting at position 47 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [msg]
ERROR StatusLogger Unrecognized conversion specifier [msg] starting at position 54 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [n]
ERROR StatusLogger Unrecognized conversion specifier [n] starting at position 56 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [d]
ERROR StatusLogger Unrecognized conversion specifier [d] starting at position 16 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [thread]
ERROR StatusLogger Unrecognized conversion specifier [thread] starting at position 25 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [level]
ERROR StatusLogger Unrecognized conversion specifier [level] starting at position 35 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [logger]
ERROR StatusLogger Unrecognized conversion specifier [logger] starting at position 47 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [msg]
ERROR StatusLogger Unrecognized conversion specifier [msg] starting at position 54 in conversion pattern.
ERROR StatusLogger Unrecognized format specifier [n]
ERROR StatusLogger Unrecognized conversion specifier [n] starting at position 56 in conversion pattern.
No protocol specified
No protocol specified
Exception in thread "main" java.lang.UnsupportedOperationException: Unable to open DISPLAY
at [email protected]/com.sun.glass.ui.gtk.GtkApplication.lambda$new$6(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Unknown Source)
at [email protected]/com.sun.glass.ui.gtk.GtkApplication.<init>(Unknown Source)
at [email protected]/com.sun.glass.ui.gtk.GtkPlatformFactory.createApplication(Unknown Source)
at [email protected]/com.sun.glass.ui.Application.run(Unknown Source)
at [email protected]/com.sun.javafx.tk.quantum.QuantumToolkit.startup(Unknown Source)
at [email protected]/com.sun.javafx.application.PlatformImpl.startup(Unknown Source)
at [email protected]/com.sun.javafx.application.PlatformImpl.startup(Unknown Source)
at [email protected]/com.sun.javafx.application.LauncherImpl.startToolkit(Unknown Source)
at [email protected]/com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
at [email protected]/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)
$ cherrytree
No protocol specified
/snap/cherrytree/40/usr/lib/python2.7/dist-packages/gtk-2.0/gtk/__init__.py:57: GtkWarning: could not open display
warnings.warn(str(e), _gtk.Warning)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:69: Warning: invalid (NULL) pointer instance
self.window = gtk.Window()
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:69: Warning: g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
self.window = gtk.Window()
/snap/cherrytree/40/usr/share/cherrytree/modules/clipboard.py:93: GtkWarning: IA__gtk_clipboard_get_for_display: assertion 'display != NULL' failed
self.clipboard = gtk.clipboard_get()
missing /home/schroeder_l/snap/cherrytree/40/.config/cherrytree/config.cfg
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:114: Warning: invalid (NULL) pointer instance
vbox_main.pack_start(self.ui.get_widget("/MenuBar"), False, False)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:114: Warning: g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
vbox_main.pack_start(self.ui.get_widget("/MenuBar"), False, False)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:114: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
vbox_main.pack_start(self.ui.get_widget("/MenuBar"), False, False)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:114: Warning: g_object_get: assertion 'G_IS_OBJECT (object)' failed
vbox_main.pack_start(self.ui.get_widget("/MenuBar"), False, False)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:114: Warning: value "TRUE" of type 'gboolean' is invalid or out of range for property 'visible' of type 'gboolean'
vbox_main.pack_start(self.ui.get_widget("/MenuBar"), False, False)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:114: GtkWarning: IA__gdk_screen_get_display: assertion 'GDK_IS_SCREEN (screen)' failed
vbox_main.pack_start(self.ui.get_widget("/MenuBar"), False, False)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:114: Warning: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
vbox_main.pack_start(self.ui.get_widget("/MenuBar"), False, False)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:119: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
self.scrolledwindow_tree = gtk.ScrolledWindow()
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:121: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
self.scrolledwindow_text = gtk.ScrolledWindow()
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:173: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
self.treeview.append_column(self.column)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:173: Warning: g_object_get: assertion 'G_IS_OBJECT (object)' failed
self.treeview.append_column(self.column)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1309: Warning: invalid (NULL) pointer instance
self.node_menu_tree = gtk.Menu()
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1309: Warning: g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
self.node_menu_tree = gtk.Menu()
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1274: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
menu_item = gtk.ImageMenuItem(attributes[1])
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1274: Warning: g_object_get: assertion 'G_IS_OBJECT (object)' failed
menu_item = gtk.ImageMenuItem(attributes[1])
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1274: Warning: value "TRUE" of type 'gboolean' is invalid or out of range for property 'visible' of type 'gboolean'
menu_item = gtk.ImageMenuItem(attributes[1])
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1276: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
menu_item.set_image(gtk.image_new_from_stock(attributes[0], gtk.ICON_SIZE_MENU))
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1276: Warning: g_object_get: assertion 'G_IS_OBJECT (object)' failed
menu_item.set_image(gtk.image_new_from_stock(attributes[0], gtk.ICON_SIZE_MENU))
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1276: Warning: value "TRUE" of type 'gboolean' is invalid or out of range for property 'visible' of type 'gboolean'
menu_item.set_image(gtk.image_new_from_stock(attributes[0], gtk.ICON_SIZE_MENU))
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1265: Warning: invalid (NULL) pointer instance
curr_submenu = gtk.Menu()
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1265: Warning: g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
curr_submenu = gtk.Menu()
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1266: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
menu_item = gtk.ImageMenuItem(attributes[1])
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1266: Warning: g_object_get: assertion 'G_IS_OBJECT (object)' failed
menu_item = gtk.ImageMenuItem(attributes[1])
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1266: Warning: value "TRUE" of type 'gboolean' is invalid or out of range for property 'visible' of type 'gboolean'
menu_item = gtk.ImageMenuItem(attributes[1])
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1267: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
menu_item.set_image(gtk.image_new_from_stock(attributes[2], gtk.ICON_SIZE_MENU))
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1267: Warning: g_object_get: assertion 'G_IS_OBJECT (object)' failed
menu_item.set_image(gtk.image_new_from_stock(attributes[2], gtk.ICON_SIZE_MENU))
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:1267: Warning: value "TRUE" of type 'gboolean' is invalid or out of range for property 'visible' of type 'gboolean'
menu_item.set_image(gtk.image_new_from_stock(attributes[2], gtk.ICON_SIZE_MENU))
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: GtkWarning: IA__gdk_pango_context_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: PangoWarning: pango_context_set_font_description: assertion 'context != NULL' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: PangoWarning: pango_context_set_base_dir: assertion 'context != NULL' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: PangoWarning: pango_context_set_language: assertion 'context != NULL' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: Warning: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: GtkWarning: IA__gtk_settings_get_for_screen: assertion 'GDK_IS_SCREEN (screen)' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: GtkWarning: IA__gdk_screen_get_display: assertion 'GDK_IS_SCREEN (screen)' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: GtkWarning: IA__gdk_keymap_get_for_display: assertion 'GDK_IS_DISPLAY (display)' failed
self.scrolledwindow_text.add(self.sourceview)
/snap/cherrytree/40/usr/share/cherrytree/modules/core.py:213: Warning: g_object_get: assertion 'G_IS_OBJECT (object)' failed
self.scrolledwindow_text.add(self.sourceview)
Segmentation fault (core dumped)
Might that problem only occur for snap apps that use GTK or Qt? Of the apps that run without problems pdftk is a command line tool and eclipse uses KDE (don't know for chromium).
