[gnome-builder] Fix meson tests introspection

[Christian Hergert <chergert src gnome org>]

commit 03ecd89b9b162a99a6a62906adffb833adf47433
Author: Sergey Shatunov <me prok pw>
Date:   Fri Mar 23 11:43:38 2018 +0000

    Fix meson tests introspection

 src/plugins/meson/gbp-meson-test-provider.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/plugins/meson/gbp-meson-test-provider.c b/src/plugins/meson/gbp-meson-test-provider.c
index 0b6264f25..9526234cc 100644
--- a/src/plugins/meson/gbp-meson-test-provider.c
+++ b/src/plugins/meson/gbp-meson-test-provider.c
@@ -208,6 +208,7 @@ gbp_meson_test_provider_do_reload (GbpMesonTestProvider *self,
   ide_subprocess_launcher_push_argv (launcher, "meson");
   ide_subprocess_launcher_push_argv (launcher, "introspect");
   ide_subprocess_launcher_push_argv (launcher, "--tests");
+  ide_subprocess_launcher_push_argv (launcher, ide_build_pipeline_get_builddir (pipeline));
 
   if (NULL == (subprocess = ide_subprocess_launcher_spawn (launcher, NULL, &error)))
     IDE_GOTO (failure);