Ok, yes, target verification fails:

```
Adding `pip' and Co. to the image packages
The target release wheezy was not found in the sources list
Traceback (most recent call last):
  File "/home/admin/bootstrap-vz/bootstrapvz/base/main.py", line 78, in run
    tasklist.run(info=bootstrap_info, dry_run=opts['--dry-run'])
  File "/home/admin/bootstrap-vz/bootstrapvz/base/tasklist.py", line 38, in run
    task.run(info)
  File "/home/admin/bootstrap-vz/bootstrapvz/plugins/pip_install/tasks.py", line 15, in run
    info.packages.add(package_name)
  File "/home/admin/bootstrap-vz/bootstrapvz/base/pkg/packagelist.py", line 96, in add
    raise PackageError(msg)
PackageError: The target release wheezy was not found in the sources list
```