xfce4-panel searches wrong directories for plugins

[vikanezrimaya]

Issue description

When I launch xfce4-panel, it searches for plugins in /run/current-system/sw/share/xfce4/panel/plugins and in /run/current-system/sw/share/xfce4/panel-plugins, but all plugins are installed into /run/current-system/sw/lib/xfce4/panel/plugins and there are not any .desktop files present at the first two paths above.

Steps to reproduce

1. Install xfce.xfce4-panel (some plugins are already included)
2. Launch strace -e open xfce4-panel 2>&1 | grep plugins to see which directories are searched for plugins and observe their absence:

open("/run/current-system/sw/share/xfce4/panel/plugins", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 ENOENT (No such file or directory)
open("/run/current-system/sw/share/xfce4/panel-plugins", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 ENOENT (No such file or directory)

Technical details

• system: "x86_64-linux"
• host os: Linux 4.14.32, NixOS, 18.03.131807.489a14add9a (Impala)
• multi-user?: yes
• sandbox: no
• version: nix-env (Nix) 2.0
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[jtojnar]

According to the patch both paths are used:

nixpkgs/pkgs/desktops/xfce/core/xfce4-panel-datadir.patch

Lines 9 to 23 in 3207b7e

	+#define DATADIR "/run/current-system/sw/share/xfce4"
	#define PANEL_PLUGINS_DATA_DIR (DATADIR G_DIR_SEPARATOR_S "panel" G_DIR_SEPARATOR_S "plugins")
	#define PANEL_PLUGINS_DATA_DIR_OLD (DATADIR G_DIR_SEPARATOR_S "panel-plugins")
	diff --git a/panel/panel-module.c b/panel/panel-module.c
	index ba39320..519440b 100644
	--- a/panel/panel-module.c
	+++ b/panel/panel-module.c
	@@ -35,6 +35,7 @@
	#include <panel/panel-plugin-external-wrapper.h>
	#include <panel/panel-plugin-external-46.h>
	+#define LIBDIR "/run/current-system/sw/lib/xfce4"
	#define PANEL_PLUGINS_LIB_DIR (LIBDIR G_DIR_SEPARATOR_S "panel" G_DIR_SEPARATOR_S "plugins")
	#define PANEL_PLUGINS_LIB_DIR_OLD (LIBDIR G_DIR_SEPARATOR_S "panel-plugins")

[vikanezrimaya]

Despite that, I don't see it opening this folder. Maybe I need to update xfce4-panel? How do I do it?

[kisik21@virtual:~]$ env DISPLAY=:0 xfce4-panel -V
xfce4-panel 4.12.1 (Xfce 4.12)

Copyright (c) 2004-2011
	The Xfce development team. All rights reserved.

Please report bugs to <http://bugzilla.xfce.org/>.

[jtojnar]

I think it searches the DATADIR for desktop files: https://wiki.xfce.org/dev/howto/panel_plugins. If so, it would not need to search LIBDIR at all.

[vikanezrimaya]

And there should be symlinks for plugin desktop files. But there are seemingly none - at least on my VM. I'm provisioning NixOS on my laptop now, will report ASAP about symlinks in DATADIR.

If there are none, we have a bug in environment build system.

[vikanezrimaya]

Updated the issue description to clarify the bug.

[jtojnar]

Did you enable the xfce module? For path to be installed to a profile (e.g. /run/current-system/sw) it needs to be listed in environment.pathsToLink, which the xfce module does:

nixpkgs/nixos/modules/services/x11/desktop-managers/xfce.nix

Line 107 in eb0943f

"/share/xfce4"

[jD91mZM2]

Wow, I just ran into this issue. I didn't figure this out until recently. Seems like something that should definitely be patched somehow so xfce4-panel can be used standalone without everyone going through the massive headache I just had. Can packages specify configuration options somehow?

[stale]

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[abathur]

Closing since it sounds like Jan answered the question, but I'm happy to reopen if I'm overreaching.