The problem is that the path that wine is trying to use to access wine.inf is wrong.
/usr/lib/i386-linux-gnu/wine-unstable/wine/../share/wine-unstable/wine.inf
for which the path can be shortened to:
/usr/lib/i386-linux-gnu/wine-unstable/share/wine-unstable/wine.inf
Which doesn't exist. The path should be:
/usr/share/wine-unstable/wine.inf
or:
/usr/lib/i386-linux-gnu/wine-unstable/wine/../../../../share/wine-unstable/wine.inf
Until the wine maintainers get a new package uploaded with a fix, the problem can be worked around by placing a symlink to /usr/share in /usr/lib/i386-linux-gnu/wine-unstable/wine/