[plt-dev] PLT interacts badly with crazy new Windows "AppData\Remote" idea

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Tue May 4 15:59:50 EDT 2010

Can the uninstaller figure out enough to delete the shadow copies of
the plt tree for the user that is running the uninstaller? (Or am I
missing something?)


On Tue, May 4, 2010 at 1:30 PM, Eli Barzilay <eli at barzilay.org> wrote:
> On May  4, Doug Williams wrote:
>> I got bitten by that back in 2008 - I have a blog entry (
>> http://drschemer.blogspot.com/2008/07/plt-scheme-on-vista.html)
>> about my problems from back then. And, I think this (
>> http://bugs.plt-scheme.org/query/?cmd=view&pr=9554) is the bug
>> report with an audit trail of e-mails.
> To summarize the problem: lots of windows applications want to write
> stuff in their directory, and this was almost always possible.  With
> the move to vista, they're trying to make things saner by protecting
> these directories (actually, the default user is not as powerful as it
> was on xp) -- and the result is that applications that expect to be
> able to write stuff this way get broken.  The UAC solution is to
> "divert" such writes to a user-local directory, so that when the
> program runs on behalf of that user it has the illusion that it can
> write there, only really it gets stored in the user directory,
> unaffecting other users or the system directory.  As expected, this
> works for many cases, and when it doesn't, the resulting confusion and
> mess is amazingly effective.  (Practically all of the problems that
> this leads to start with mysterious voodoo bug reports, which sound
> utterly confused and impossible to recreate.)
>> I'm not sure if the installer was ever updated to know about the shadow
>> copy. Eli and Matthew (and probably others) identified the problem.
> The installer (or uninstaller) cannot be fixed to deal with it -- as
> usual, the immediate way to see this is to consider a system with
> multiple users: if I uninstall, you won't like it if it makes the
> system delete your files.
> IIRC, there was some bit to set somewhere declaring that the
> application is well behaved, and just disable the UAC "feature", and
> I'm not sure if there were other problems in turning it on.
> --
>          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
>                    http://barzilay.org/                   Maze is Life!
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