Don't try to read dpkg database unless its directory is accessible to us.
treeea6d231172b7dcd82a28189c50b616d2625e6a58
-rwxr-xr-x 6044 0alias
-rw-r--r-- 2109 0alias.1
-rwxr-xr-x 93 0launch
-rw-r--r-- 7692 0launch.1
-rwxr-xr-x 2194 0store
-rwxr-xr-x 624 0store-secure-add
-rw-r--r-- 2714 0store-secure-add.1
-rw-r--r-- 4161 0store.1
-rw-r--r-- 26536 COPYING
-rw-r--r-- 2115 README
-rw-r--r-- 2324 ZeroInstall.xml
drwxr-xr-x - applications
-rw-r--r-- 67 setup.cfg
-rw-r--r-- 2405 setup.py
drwxr-xr-x - tests
drwxr-xr-x - zeroinstall