Check that missing subdirs cause an error.

meson.py

@@ -138,7 +138,7 @@ if __name__ == '__main__':
             else:
                 mlog.log(mlog.red('\nMeson encountered an error:'))
             mlog.log(e)
-            sys.exit(1)
         else:
             traceback.print_exc()
+        sys.exit(1)
 

test cases/failing/3 missing subdir/meson.build

@@ -0,0 +1,3 @@
+project('subdir', 'c')
+
+subdir('missing')

test cases/failing/4 missing meson.build/meson.build

@@ -0,0 +1,3 @@
+project('missing meson.build', 'c')
+
+subdir('subdir')

test cases/failing/4 missing meson.build/subdir/dummy.txt

@@ -0,0 +1 @@
+This needs to be here because Git can't handle empty dirs.