Best way to overlay a filesystem for a Wine app?

[Dan Kegel]

On Sun, Jan 29, 2012 at 3:58 PM, Scott Ritchie <scott at open-vote.org> wrote:
>> - rely on the system's update manager to pull updated versions of the
>> package from the repository
>
> This may not be a fast-enough option for some apps, such as online games
> that need to keep everyone in version sync.  Even in an ideal case where
> the company was 100% behind the Ubuntu package and kept it in sync with
> their release process, there is still no current way for the Windows app
> to tell Apt to update its package.

In those cases, you would make the files updated by the game's launcher
be read/write instead of read only symlinks.

> wouldn't a
> unionfs-fuse overlay be simpler and cleaner than this since you wouldn't
> have to worry about the app-specific stuff at all?

Yes.  My experiences were in the context of making a single portable
(in the old sense of the word) binary to run on all sorts of distros,
even old ones with no union filesystem support at all, so we had to
use symlinks.
And my impression is that filesystem unions aren't quite ready for
prime time.  LWN has had a lot of articles about that (most recently last June?
http://lwn.net/Articles/447650/ )  But perhaps you are only targeting the
most recent Ubuntu, and have found that it includes a usable union
mount of some sort.

When I try to script things that use fuse filesystems, I seem to need to
add mystery "sleep 1" statements after issuing mount commands, which
isn't exactly trust-inspiring.  But maybe some other part of the system
I was using was causing the delay.

>> (Picasa also went further and bundled a snapshot of wine, too, and
>> modified the app slightly to display unix paths, which required adding
>> one little extension to wine.  I'm sure the wine patch is around if
>> someone wants it.
>
> This patch would be interesting if you could dig it up.

I don't see it standalone anywhere, but the source tarball used is linked
to from http://code.google.com/opensource/wine.html, and the extension
was probably kernel32.wine_get_unix_real_name().

> I don't know if
> Alexandre would accept it, but ideally it would be part of Wine and
> turned on via an environment variable or command line switch.

I doubt he would accept it.  (Heck, he probably wrote it.)
- Dan