[xdg-desktop-portal-gnome/abderrahim/systemd-unit] meson.build: use the systemd pkg-config file to find the unit directory

[Abderrahim Kitouni <akitouni src gnome org>]

commit 6db9ad2b8900e192f9364d657ada4b7d8f45a568
Author: Abderrahim Kitouni <akitouni gnome org>
Date:   Thu Aug 19 09:39:06 2021 +0100

    meson.build: use the systemd pkg-config file to find the unit directory

 meson.build | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index d2fc58b..d9baeba 100644
--- a/meson.build
+++ b/meson.build
@@ -13,7 +13,11 @@ libexecdir = get_option('libexecdir')
 
 systemduserunitdir = get_option('systemduserunitdir')
 if systemduserunitdir == ''
-  systemduserunitdir = libdir / 'systemd' / 'user'
+  systemd = dependency('systemd', version: '>= 242')
+  systemduserunitdir = systemd.get_pkgconfig_variable(
+    'systemduserunitdir',
+    define_variable: ['prefix', get_option('prefix')]
+  )
 endif
 
 dbus_service_dir = get_option('dbus_service_dir')