fixup! Add meson build system

Use auto feature for introspection.

.github/workflows/test.yaml

@@ -42,11 +42,11 @@ jobs:
         strategy:
             matrix:
                 configureFlags:
-                    - "-Dintrospection=false -Dglib=disabled"
-                    - "-Dglib=disabled"
+                    - ""
+                    - "-Dglib=enabled -Dintrospection=enabled"
                     - "-Dgegl=enabled"
                 include:
-                    - configureFlags: "-Dglib=enabled"
+                    - configureFlags: "-Dglib=enabled -Dintrospection=enabled"
                       extraDeps: "libgirepository1.0-dev"
                     - configureFlags: "-Dgegl=enabled"
                       extraDeps: "libgegl-dev"

gegl/meson.build

@@ -30,7 +30,7 @@ install_headers(
 )
 
 
-if get_option('introspection')
+if use_introspection
   gnome = import('gnome')
 
   libmypaint_gegl_gir = gnome.generate_gir(

meson.build

@@ -93,6 +93,20 @@ if use_gegl
 endif
 
 introspection_required_version = '1.32.0'
+introspection_feature = get_option(
+  'introspection',
+).require(
+  use_glib,
+  error_message: 'Generating GObject introspection requires building with GLib support',
+)
+# For g-ir-scanner and g-ir-compiler as used by the gnome module.
+gi = dependency(
+  'gobject-introspection-1.0',
+  version: f'>=@introspection_required_version@',
+  required: introspection_feature,
+  native: true,
+)
+use_introspection = gi.found()
 
 
 # OpenMP
@@ -235,11 +249,7 @@ libmypaint = library(
   install: true,
 )
 
-
-if get_option('introspection')
-  if not use_glib
-    error('Generating GObject introspection requires building with GLib support')
-  endif
+if use_introspection
   gnome = import('gnome')
 
   libmypaint_gir = gnome.generate_gir(

meson_options.txt

@@ -44,7 +44,7 @@ option(
 )
 option(
   'introspection',
-  type: 'boolean',
-  value: true,
-  description: 'Enable GObject Instrospection',
+  type: 'feature',
+  value: 'auto',
+  description: 'Enable GObject Instrospection (requires glib feature)',
 )