diff -Nru python-apt-1.0.0~beta2/apt/cache.py python-apt-1.0.0~beta3/apt/cache.py
--- python-apt-1.0.0~beta2/apt/cache.py	2015-06-12 22:42:01.000000000 +0000
+++ python-apt-1.0.0~beta3/apt/cache.py	2015-06-17 16:29:02.000000000 +0000
@@ -23,6 +23,7 @@
 
 import fnmatch
 import os
+import warnings
 import weakref
 
 import apt_pkg
@@ -78,6 +79,7 @@
         self._records = None
         self._list = None
         self._callbacks = {}
+        self._callbacks2 = {}
         self._weakref = weakref.WeakValueDictionary()
         self._changes_count = -1
         self._sorted_set = None
@@ -144,6 +146,10 @@
                 else:
                     callback()
 
+        if name in self._callbacks2:
+            for callback, args, kwds in self._callbacks2[name]:
+                    callback(self, *args, **kwds)
+
     def open(self, progress=None):
         """ Open the package cache, after that it can be used like
             a dictionary
@@ -539,12 +545,40 @@
         self._run_callbacks("cache_pre_change")
 
     def connect(self, name, callback):
-        """ connect to a signal, currently only used for
-            cache_{post,pre}_{changed,open} """
+        """Connect to a signal.
+
+        .. deprecated:: 1.0
+
+            Please use connect2() instead, as this function is very
+            likely to cause a memory leak.
+        """
+        if callback != '_inc_changes_count':
+            warnings.warn("connect() likely causes a reference"
+                          " cycle, use connect2() instead", RuntimeWarning, 2)
         if name not in self._callbacks:
             self._callbacks[name] = []
         self._callbacks[name].append(callback)
 
+    def connect2(self, name, callback, *args, **kwds):
+        """Connect to a signal.
+
+        The callback will be passed the cache as an argument, and
+        any arguments passed to this function. Make sure that, if you
+        pass a method of a class as your callback, your class does not
+        contain a reference to the cache.
+
+        Cyclic references to the cache can cause issues if the Cache object
+        is replaced by a new one, because the cache keeps a lot of objects and
+        tens of open file descriptors.
+
+        currently only used for cache_{post,pre}_{changed,open}.
+
+        .. versionadded:: 1.0
+        """
+        if name not in self._callbacks2:
+            self._callbacks2[name] = []
+        self._callbacks2[name].append((callback, args, kwds))
+
     def actiongroup(self):
         """Return an `ActionGroup` object for the current cache.
 
@@ -664,6 +698,38 @@
             return False
 
 
+class _FilteredCacheHelper(object):
+    """Helper class for FilteredCache to break a reference cycle."""
+
+    def __init__(self, cache):
+        # Do not keep a reference to the cache, or you have a cycle!
+
+        self._filtered = {}
+        self._filters = {}
+        cache.connect2("cache_post_change", self.filter_cache_post_change)
+        cache.connect2("cache_post_open", self.filter_cache_post_change)
+
+    def _reapply_filter(self, cache):
+        " internal helper to refilter "
+        # Do not keep a reference to the cache, or you have a cycle!
+        self._filtered = {}
+        for pkg in cache:
+            for f in self._filters:
+                if f.apply(pkg):
+                    self._filtered[pkg.name] = 1
+                    break
+
+    def set_filter(self, filter):
+        """Set the current active filter."""
+        self._filters = []
+        self._filters.append(filter)
+
+    def filter_cache_post_change(self, cache):
+        """Called internally if the cache changes, emit a signal then."""
+        # Do not keep a reference to the cache, or you have a cycle!
+        self._reapply_filter(cache)
+
+
 class FilteredCache(object):
     """ A package cache that is filtered.
 
@@ -675,66 +741,50 @@
             self.cache = Cache(progress)
         else:
             self.cache = cache
-        self.cache.connect("cache_post_change", self.filter_cache_post_change)
-        self.cache.connect("cache_post_open", self.filter_cache_post_change)
-        self._filtered = {}
-        self._filters = []
+        self._helper = _FilteredCacheHelper(self.cache)
 
     def __len__(self):
-        return len(self._filtered)
+        return len(self._helper._filtered)
 
     def __getitem__(self, key):
         return self.cache[key]
 
     def __iter__(self):
-        for pkgname in self._filtered:
+        for pkgname in self._helper._filtered:
             yield self.cache[pkgname]
 
     def keys(self):
-        return self._filtered.keys()
+        return self._helper._filtered.keys()
 
     def has_key(self, key):
-        return (key in self._filtered)
+        return key in self
 
     def __contains__(self, key):
-        return (key in self._filtered)
-
-    def _reapply_filter(self):
-        " internal helper to refilter "
-        self._filtered = {}
-        for pkg in self.cache:
-            for f in self._filters:
-                if f.apply(pkg):
-                    self._filtered[pkg.name] = 1
-                    break
+        try:
+            # Normalize package name for multi arch
+            return self.cache[key].name in self._helper._filtered
+        except KeyError:
+            return False
 
     def set_filter(self, filter):
         """Set the current active filter."""
-        self._filters = []
-        self._filters.append(filter)
-        #self._reapplyFilter()
-        # force a cache-change event that will result in a refiltering
+        self._helper.set_filter(filter)
         self.cache.cache_post_change()
 
     def filter_cache_post_change(self):
         """Called internally if the cache changes, emit a signal then."""
-        #print "filterCachePostChange()"
-        self._reapply_filter()
-
-#    def connect(self, name, callback):
-#        self.cache.connect(name, callback)
+        self._helper.filter_cache_post_change(self.cache)
 
     def __getattr__(self, key):
         """we try to look exactly like a real cache."""
-        #print "getattr: %s " % key
         return getattr(self.cache, key)
 
 
-def cache_pre_changed():
+def cache_pre_changed(cache):
     print("cache pre changed")
 
 
-def cache_post_changed():
+def cache_post_changed(cache):
     print("cache post changed")
 
 
@@ -743,8 +793,8 @@
     print("Cache self test")
     apt_pkg.init()
     cache = Cache(apt.progress.text.OpProgress())
-    cache.connect("cache_pre_change", cache_pre_changed)
-    cache.connect("cache_post_change", cache_post_changed)
+    cache.connect2("cache_pre_change", cache_pre_changed)
+    cache.connect2("cache_post_change", cache_post_changed)
     print(("aptitude" in cache))
     pkg = cache["aptitude"]
     print(pkg.name)
@@ -771,8 +821,8 @@
 
     print("Testing filtered cache (argument is old cache)")
     filtered = FilteredCache(cache)
-    filtered.cache.connect("cache_pre_change", cache_pre_changed)
-    filtered.cache.connect("cache_post_change", cache_post_changed)
+    filtered.cache.connect2("cache_pre_change", cache_pre_changed)
+    filtered.cache.connect2("cache_post_change", cache_post_changed)
     filtered.cache.upgrade()
     filtered.set_filter(MarkedChangesFilter())
     print(len(filtered))
@@ -783,8 +833,8 @@
 
     print("Testing filtered cache (no argument)")
     filtered = FilteredCache(progress=apt.progress.base.OpProgress())
-    filtered.cache.connect("cache_pre_change", cache_pre_changed)
-    filtered.cache.connect("cache_post_change", cache_post_changed)
+    filtered.cache.connect2("cache_pre_change", cache_pre_changed)
+    filtered.cache.connect2("cache_post_change", cache_post_changed)
     filtered.cache.upgrade()
     filtered.set_filter(MarkedChangesFilter())
     print(len(filtered))
diff -Nru python-apt-1.0.0~beta2/data/templates/Ubuntu.mirrors python-apt-1.0.0~beta3/data/templates/Ubuntu.mirrors
--- python-apt-1.0.0~beta2/data/templates/Ubuntu.mirrors	2015-06-12 22:42:40.000000000 +0000
+++ python-apt-1.0.0~beta3/data/templates/Ubuntu.mirrors	2015-06-17 16:29:38.000000000 +0000
@@ -203,6 +203,7 @@
 http://kartolo.sby.datautama.net.id/ubuntu/
 http://kebo.pens.ac.id/ubuntu/
 http://mirror.kavalinux.com/ubuntu/
+http://mirror.poliwangi.ac.id/ubuntu/
 http://mirror.unej.ac.id/ubuntu/
 http://suro.ubaya.ac.id/ubuntu/
 #LOC:IE
@@ -212,7 +213,6 @@
 #LOC:IN
 ftp://ftp.iitb.ac.in/distributions/ubuntu/archives/
 http://ftp.iitm.ac.in/ubuntu/
-http://mirror.cse.iitk.ac.in/ubuntu/
 #LOC:IR
 http://mirror.iranserver.com/ubuntu/
 http://ubuntu.asis.io/
@@ -370,7 +370,6 @@
 http://mirror01.idc.hinet.net/ubuntu/
 http://tw.archive.ubuntu.com/ubuntu/
 http://ubuntu.cs.nctu.edu.tw/ubuntu/
-http://ubuntu.stu.edu.tw/ubuntu/
 #LOC:TZ
 http://deb-mirror.habari.co.tz/ubuntu/
 http://mirror.aptus.co.tz/pub/ubuntuarchive/
@@ -452,6 +451,7 @@
 http://ubuntu.wikimedia.org/ubuntu/
 http://ubuntuarchive.mirror.nac.net/
 http://us.archive.ubuntu.com/ubuntu/
+http://www.club.cc.cmu.edu/pub/ubuntu/
 http://www.gtlib.gatech.edu/pub/ubuntu/
 http://www.lug.bu.edu/mirror/ubuntu/
 #LOC:UZ
diff -Nru python-apt-1.0.0~beta2/debian/changelog python-apt-1.0.0~beta3/debian/changelog
--- python-apt-1.0.0~beta2/debian/changelog	2015-06-12 22:42:01.000000000 +0000
+++ python-apt-1.0.0~beta3/debian/changelog	2015-06-17 16:29:02.000000000 +0000
@@ -1,3 +1,16 @@
+python-apt (1.0.0~beta3) unstable; urgency=medium
+
+  * tests/test_paths.py: Catch and assert the DeprecationWarning
+  * setup.py: If no version is in the environment, return None
+  * doc/source/library/apt_pkg.rst: Fix an example from old API to new API
+  * apt.cache.FilteredCache: Fix multi-arch package lookups
+  * apt.Cache: Introduce a connect2() callback connector
+  * Break the FilteredCache <-> Cache reference cycle
+  * apt.Cache: Issue a RuntimeWarning in connect()
+  * doc: whatsnew: Document what's new in beta3
+
+ -- Julian Andres Klode <jak@debian.org>  Wed, 17 Jun 2015 18:28:44 +0200
+
 python-apt (1.0.0~beta2) unstable; urgency=low
 
   * debian/control: Build-Depend on apt (>= 1.0.9.4) for Files2()
diff -Nru python-apt-1.0.0~beta2/doc/source/library/apt_pkg.rst python-apt-1.0.0~beta3/doc/source/library/apt_pkg.rst
--- python-apt-1.0.0~beta2/doc/source/library/apt_pkg.rst	2015-06-12 22:42:01.000000000 +0000
+++ python-apt-1.0.0~beta3/doc/source/library/apt_pkg.rst	2015-06-17 16:29:02.000000000 +0000
@@ -1352,10 +1352,10 @@
 
         Example (shortened)::
 
-            cand = depcache.GetCandidateVer(cache['python-apt'])
-            records.Lookup(cand.FileList[0])
+            cand = depcache.get_candidate_ver(cache['python-apt'])
+            records.lookup(cand.file_list[0])
             # Now you can access the record
-            print records.SourcePkg # == python-apt
+            print records.source_pkg # == python-apt
 
     .. attribute:: filename
 
diff -Nru python-apt-1.0.0~beta2/doc/source/whatsnew/1.0.rst python-apt-1.0.0~beta3/doc/source/whatsnew/1.0.rst
--- python-apt-1.0.0~beta2/doc/source/whatsnew/1.0.rst	2015-06-12 22:42:01.000000000 +0000
+++ python-apt-1.0.0~beta3/doc/source/whatsnew/1.0.rst	2015-06-17 16:29:02.000000000 +0000
@@ -10,9 +10,14 @@
 * A new a :meth:`apt_pkg.TagFile.close` method was added
 * :class:`apt_pkg.TagFile` is now a context manager
 
-* The high-level cache class, :class:`apt.cache.Cache` now supports package
+* The high-level cache class, :class:`apt.cache.Cache` and it's companion
+  :class:`apt.cache.FilteredCache` now support package
   names with special architecture qualifiers such as :all and :native.
 
+* The method :meth:`apt.cache.Cache.connect2` allows connecting callbacks on
+  cache changes that take the cache as their first argument, reducing the
+  potential for reference cycles.
+
 Deprecated
 ----------
 The following features are deprecated, starting with this release:
@@ -21,6 +26,9 @@
 * The `files` member of of :class:`apt_pkg.SourceRecords`
 * The `md5` argument to :class:`apt_pkg.AcquireFile`, it is replaced by
   the `hash` argument.
+* The method :meth:`apt.cache.Cache.connect` has been deprecated. It is
+  replaced by :meth:`apt.cache.Cache.connect2` which is more flexible and
+  less prone to reference cycles.
 
 Removed
 -------
@@ -36,6 +44,10 @@
 
 Maintenance
 -----------
+* The classes :class:`apt.cache.Cache` and :class:`apt.cache.FilteredCache` no
+  longer store cyclic references to/between them. This fixes a huge issue,
+  because a cache can have tens of open file descriptors, causing the maximum
+  of file descriptors to be reached easily.
 
 * :mod:`apt_inst` now supports ar and tar archives that are larger than 4 GiB
 * Various smaller bug fixes
diff -Nru python-apt-1.0.0~beta2/setup.py python-apt-1.0.0~beta3/setup.py
--- python-apt-1.0.0~beta2/setup.py	2015-06-12 22:42:01.000000000 +0000
+++ python-apt-1.0.0~beta3/setup.py	2015-06-17 16:29:02.000000000 +0000
@@ -28,6 +28,9 @@
 def get_version():
     """Get a PEP 0440 compatible version string"""
     version = os.environ.get('DEBVER')
+    if not version:
+        return version
+
     version = version.replace("~alpha", ".a")
     version = version.replace("~beta", ".b")
     version = version.replace("~rc", ".rc")
diff -Nru python-apt-1.0.0~beta2/tests/test_paths.py python-apt-1.0.0~beta3/tests/test_paths.py
--- python-apt-1.0.0~beta2/tests/test_paths.py	2015-06-12 22:42:01.000000000 +0000
+++ python-apt-1.0.0~beta3/tests/test_paths.py	2015-06-17 16:29:02.000000000 +0000
@@ -4,6 +4,7 @@
 import os
 import shutil
 import unittest
+import warnings
 
 import apt_inst
 import apt_pkg
@@ -40,10 +41,19 @@
         Ensure that both "md5" and "hash" is supported as keyword for
         AcquireFile
         """
-        apt_pkg.AcquireFile(
-            apt_pkg.Acquire(), "http://example.com",
-            destfile=self.file_bytes,
-            md5="abcdef")
+        with warnings.catch_warnings(record=True) as caught_warnings:
+            warnings.simplefilter("always")
+            apt_pkg.AcquireFile(
+                apt_pkg.Acquire(), "http://example.com",
+                destfile=self.file_bytes,
+                md5="abcdef")
+
+        self.assertEqual(len(caught_warnings), 1)
+        self.assertTrue(issubclass(caught_warnings[0].category,
+                                   DeprecationWarning))
+        self.assertIn("md5", str(caught_warnings[0].message))
+        self.assertIn("hash", str(caught_warnings[0].message))
+
         apt_pkg.AcquireFile(
             apt_pkg.Acquire(), "http://example.com",
             destfile=self.file_bytes,