[gnome-builder] build: use ignore_headers from meson gtk-doc

[Christian Hergert <chergert src gnome org>]

commit e429525e4f13e2394e529691c182a6a56a8060b5
Author: Christian Hergert <chergert redhat com>
Date:   Sun Nov 5 20:49:41 2017 -0800

    build: use ignore_headers from meson gtk-doc

 doc/sdk/meson.build |    4 +++-
 meson.build         |    2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/doc/sdk/meson.build b/doc/sdk/meson.build
index d510709..7569eec 100644
--- a/doc/sdk/meson.build
+++ b/doc/sdk/meson.build
@@ -5,6 +5,7 @@ foreach source : libide_private_sources
   private_headers += ['@0@/@1@'.format(meson.source_root(), source)]
 endforeach
 
+# Locate the dependency documentation location to fix cross-references
 libdazzle_prefix = dependency('libdazzle-1.0').get_pkgconfig_variable('prefix')
 libdazzle_docpath = join_paths(libdazzle_prefix, 'share', 'gtk-doc', 'html')
 glib_prefix = dependency('glib-2.0').get_pkgconfig_variable('prefix')
@@ -22,6 +23,7 @@ gsv_docpath = join_paths(gsv_prefix, 'share', 'gtk-doc', 'html')
 vte_prefix = dependency('vte-2.91').get_pkgconfig_variable('prefix')
 vte_docpath = join_paths(vte_prefix, 'share', 'vte-doc', 'html')
 
+# Locate our directory for documentation
 docpath = join_paths(get_option('datadir'), 'gtk-doc', 'html')
 
 gnome.gtkdoc('libide',
@@ -36,8 +38,8 @@ gnome.gtkdoc('libide',
           scan_args: [
             '--rebuild-types',
             '--ignore-decorators=_IDE_EXTERN',
-            '--ignore-headers=' + ' '.join(private_headers),
           ],
+     ignore_headers: private_headers,
 
        fixxref_args: [
          '--html-dir=@0@'.format(docpath),
diff --git a/meson.build b/meson.build
index c09d04b..78ec6be 100644
--- a/meson.build
+++ b/meson.build
@@ -1,7 +1,7 @@
 project('gnome-builder', 'c',
           license: 'GPL3+',
           version: '3.27.1',
-    meson_version: '>= 0.40.1',
+    meson_version: '>= 0.42.0',
   default_options: [
                      'c_std=gnu11',
                      'cpp_std=c++11',