MSIX Packaging Tool Failures: File not found issues (A workaround)

In packaging a lot of apps, I find that the Packaging tool fails quite often when saving the package.  In looking into the Log file, these errors are usually background system created files.  Like C:\Windows\System32\config\SYSTEM.LOG1 or LOG2.  Or those stupid wbem files.

Adding exclusions doesn't seem to help.  I even add them in the form shown, or in \\?\C:\Windows... form (as the log file hints at).  Still doesn't help.  Even though the files are in the exclusion list, they don't get excluded.  

One possible cause of this is hinted at by the workaround that I am using.  Rather than save the package off and have it fail, I find I must continue into the package editor.  From there I can manually look for potentially offending files and right-click delete them.  Then I can save the package off cleanly.

So what's the hint about the possible cause?  Well when you add an exclusion (on an x64 OS) to C:\Windows\System32\config\SYSTEM.LOG1, this exclusion is mapped to and saved as "[{AppVPackageRoot}]\config\SYSTEM.LOG1"  (where the default [{AppVPackageRoot}] points to the system32 folder).  I previously commented that this is a horrible mapping, as one might set the package root manually in which case this points to a different place.  And that does need to be addressed, but I wasn't doing that here - I was not specifying the installation folder.  No, the possible cause is seen inside the editor where the captured file is actually mapped differently, as "[{System}]\config\SYSTEM.LOG1".  Which of course is a different folder (but also in the exclusion list).

So it seems that the exclusion filtering is horribly confused by these variables and needs to be fixed. But at least with a work-around I can start packaging again!