Scratch fails to write to Scratch.activity/Projects

[Mikus Grinbergs]

> Scratch-6.xo is now at
> http://dev.laptop.org/~cscott/bundles/Scratch-6.xo

I attempted to install Scratch-6.xo with 'sugar-install-bundle'.

Aside from LOTS of warning messages about invalid entries in 
MANIFEST, the bundle install crashed with

> Traceback (most recent call last):
>   File "/usr/bin/sugar-install-bundle", line 18, in <module>
>     bundle.install()
>   File "/usr/lib/python2.5/site-packages/sugar/bundle/activitybundle.py", line 362, in install
>     install_path = self.unpack(install_dir)
>   File "/usr/lib/python2.5/site-packages/sugar/bundle/activitybundle.py", line 287, in unpack
>     self._unzip(install_dir)
>   File "/usr/lib/python2.5/site-packages/sugar/bundle/bundle.py", line 166, in _unzip
>     raise ZipExtractException
> sugar.bundle.bundle.ZipExtractException

mikus