Check for required Python modules by default

Add meson custom option 'check-py-modules' to turn this off

Signed-off-by: Christopher Arndt <chris@chrisarndt.de>

meson.build

@@ -31,7 +31,11 @@ endif
 
 if get_option('gui').enabled()
     pymod = import('python')
-    python = pymod.find_installation('python3', required: true)
+    python = pymod.find_installation(
+        'python3',
+        required: true,
+        modules: get_option('check-py-modules') ? ['gi', 'cairo', 'xdg'] : []
+    )
 endif
 
 # Installation directories

meson_options.txt

@@ -8,6 +8,11 @@ option('jack-midi',
     value: 'enabled',
     description: 'Enable JACK MIDI support'
 )
+option('check-py-modules',
+    type: 'boolean',
+    value: true,
+    description: 'Check whether required Python modules are installed'
+)
 option('verbose',
     type: 'boolean',
     value: false,