Unknown '' tag name from a WiX Object (wixobj) file

[nazar-pc]

I was trying to add some conditional logic inside of <Wix> element like this:

<Wix xmlns='http://schemas.microsoft.com/wix/2006/wi'
     xmlns:bal='http://schemas.microsoft.com/wix/BalExtension'
     xmlns:util='http://schemas.microsoft.com/wix/UtilExtension'>
<?ifdef env.WIX_BUNDLE ?>
<?define WIX_BUNDLE = $(env.WIX_BUNDLE) ?>
<?else?>
<?define WIX_BUNDLE = 0 ?>
<?endif?>
<?if $(var.WIX_BUNDLE) = "1" ?>

But got the following error:

Error[2] (Generic): Unknown '' tag name from a WiX Object (wixobj) file.

Would be nice to improve parsing logic a little bit to ignore various preprocessor elements.