(doc) A bit more about current problems

README.txt

@@ -339,11 +339,11 b' particular, those can manifest by:'
 Those almost always mean that *natural* keyring backend for given
 desktop type doesn't work, or is not present at all.  For example,
 some necessary runtime component can be down (say, you use Linux, but
-have neither Gnome Keyring, nor KDE Wallet, running). Or appropriate
-backend is not installed because it could not be build during
-keyring_ library installation (maybe because some required library
-was not present at the moment of keyring installation, or maybe because compiler
-as such is not present on the system).
+neither Gnome Keyring, nor KDE Wallet, is running). Or appropriate
+backend is not installed because it could not be build during keyring_
+library installation (maybe because some required library was not
+present at the moment of keyring installation, or maybe because
+compiler as such is not present on the system).
 
 To diagnose such problems, try using ``keyring`` utility, as described
 on keyring_ documentation page, for example by::
@@ -365,17 +365,23 b' for further pointers in keyring_ documen'
 list, or issue tracker. Typically it will turn out, that you need to
 install some missing tool, or library, and reinstall keyring.
 
+.. note::
+
+   Recent versions of keyring library (since version 12) use python
+   entrypoints to find available backends. Those are incompatible with
+   some binary packaging methods (like ``py2app``) and may cause
+   problems. In particular there were packaged installations of TortoiseHG
+   which were unable to load keyring backends. See `#61 <https://bitbucket.org/Mekk/mercurial_keyring/issues/61/tortoisehg-encounters-unknown-exception>`_ for some more details.
+
 If ``keyring`` command works, but mercurial with mercurial_keyring does not,
 try enforcing  proper backend (by means of ``keyringrc.cfg``, see above).
 Only if this doesn't help, there may be a bug in mercurial_keyring.
 
-.. note::
-
-   By far easiest way to have properly working keyring is to use
-   packaged binary version (like ``python-keyring`` Ubuntu package, or
-   keyring bundled with TortoiseHG on some systems). If you pip-installed
-   keyring and it doesn't work, you may consider ``pip uninstall keyring``
-   and look for binary package instead.
+By far easiest way to have properly working keyring is to use packaged
+binary version (like ``python-keyring`` Ubuntu package, or keyring
+bundled with TortoiseHG on some systems). If you pip-installed keyring
+and it doesn't work, you may consider removing it via ``pip uninstall
+keyring`` and looking for binary package instead.