diff --git a/PKG-INFO b/PKG-INFO
index c1816fd8..ef1fa92e 100644
--- a/PKG-INFO
+++ b/PKG-INFO
@@ -1,216 +1,216 @@
 Metadata-Version: 2.1
 Name: swh.storage
-Version: 0.1.0
+Version: 0.1.1
 Summary: Software Heritage storage manager
 Home-page: https://forge.softwareheritage.org/diffusion/DSTO/
 Author: Software Heritage developers
 Author-email: swh-devel@inria.fr
 License: UNKNOWN
 Project-URL: Bug Reports, https://forge.softwareheritage.org/maniphest
 Project-URL: Funding, https://www.softwareheritage.org/donate
 Project-URL: Source, https://forge.softwareheritage.org/source/swh-storage
 Project-URL: Documentation, https://docs.softwareheritage.org/devel/swh-storage/
 Description: swh-storage
         ===========
         
         Abstraction layer over the archive, allowing to access all stored source code
         artifacts as well as their metadata.
         
         See the
         [documentation](https://docs.softwareheritage.org/devel/swh-storage/index.html)
         for more details.
         
         ## Quick start
         
         ### Dependencies
         
         Python tests for this module include tests that cannot be run without a local
         Postgresql database, so you need the Postgresql server executable on your
         machine (no need to have a running Postgresql server). They also expect a
         cassandra server.
         
         #### Debian-like host
         
         ```
         $ sudo apt install libpq-dev postgresql-11 cassandra
         ```
         
         #### Non Debian-like host
         
         The tests expects `/usr/sbin/cassandra` to exist.
         
         Optionally, you can avoid running the cassandra tests.
         
         ```
         (swh) :~/swh-storage$ tox -- -m 'not cassandra'
         ```
         
         ### Installation
         
         It is strongly recommended to use a virtualenv. In the following, we
         consider you work in a virtualenv named `swh`. See the
         [developer setup guide](https://docs.softwareheritage.org/devel/developer-setup.html#developer-setup)
         for a more details on how to setup a working environment.
         
         
         You can install the package directly from
         [pypi](https://pypi.org/p/swh.storage):
         
         ```
         (swh) :~$ pip install swh.storage
         [...]
         ```
         
         Or from sources:
         
         ```
         (swh) :~$ git clone https://forge.softwareheritage.org/source/swh-storage.git
         [...]
         (swh) :~$ cd swh-storage
         (swh) :~/swh-storage$ pip install .
         [...]
         ```
         
         Then you can check it's properly installed:
         ```
         (swh) :~$ swh storage --help
         Usage: swh storage [OPTIONS] COMMAND [ARGS]...
         
           Software Heritage Storage tools.
         
         Options:
           -h, --help  Show this message and exit.
         
         Commands:
           rpc-serve  Software Heritage Storage RPC server.
         ```
         
         
         ## Tests
         
         The best way of running Python tests for this module is to use
         [tox](https://tox.readthedocs.io/).
         
         ```
         (swh) :~$ pip install tox
         ```
         
         ### tox
         
         From the sources directory, simply use tox:
         
         ```
         (swh) :~/swh-storage$ tox
         [...]
         ========= 315 passed, 6 skipped, 15 warnings in 40.86 seconds ==========
         _______________________________ summary ________________________________
           flake8: commands succeeded
           py3: commands succeeded
           congratulations :)
         ```
         
         ## Development
         
         The storage server can be locally started. It requires a configuration file and
         a running Postgresql database.
         
         ### Sample configuration
         
         A typical configuration `storage.yml` file is:
         
         ```
         storage:
           cls: local
           args:
             db: "dbname=softwareheritage-dev user=<user> password=<pwd>"
             objstorage:
               cls: pathslicing
               args:
                 root: /tmp/swh-storage/
                 slicing: 0:2/2:4/4:6
         ```
         
         which means, this uses:
         
         - a local storage instance whose db connection is to
           `softwareheritage-dev` local instance,
         
         - the objstorage uses a local objstorage instance whose:
         
           - `root` path is /tmp/swh-storage,
         
           - slicing scheme is `0:2/2:4/4:6`. This means that the identifier of
             the content (sha1) which will be stored on disk at first level
             with the first 2 hex characters, the second level with the next 2
             hex characters and the third level with the next 2 hex
             characters. And finally the complete hash file holding the raw
             content. For example: 00062f8bd330715c4f819373653d97b3cd34394c
             will be stored at 00/06/2f/00062f8bd330715c4f819373653d97b3cd34394c
         
         Note that the `root` path should exist on disk before starting the server.
         
         
         ### Starting the storage server
         
         If the python package has been properly installed (e.g. in a virtual env), you
         should be able to use the command:
         
         ```
         (swh) :~/swh-storage$ swh storage rpc-serve storage.yml
         ```
         
         This runs a local swh-storage api at 5002 port.
         
         ```
         (swh) :~/swh-storage$ curl http://127.0.0.1:5002
         <html>
         <head><title>Software Heritage storage server</title></head>
         <body>
         <p>You have reached the
         <a href="https://www.softwareheritage.org/">Software Heritage</a>
         storage server.<br />
         See its
         <a href="https://docs.softwareheritage.org/devel/swh-storage/">documentation
         and API</a> for more information</p>
         ```
         
         ### And then what?
         
         In your upper layer
         ([loader-git](https://forge.softwareheritage.org/source/swh-loader-git/),
         [loader-svn](https://forge.softwareheritage.org/source/swh-loader-svn/),
         etc...), you can define a remote storage with this snippet of yaml
         configuration.
         
         ```
         storage:
           cls: remote
           args:
             url: http://localhost:5002/
         ```
         
         You could directly define a local storage with the following snippet:
         
         ```
         storage:
           cls: local
           args:
             db: service=swh-dev
             objstorage:
               cls: pathslicing
               args:
                 root: /home/storage/swh-storage/
                 slicing: 0:2/2:4/4:6
         ```
         
 Platform: UNKNOWN
 Classifier: Programming Language :: Python :: 3
 Classifier: Intended Audience :: Developers
 Classifier: License :: OSI Approved :: GNU General Public License v3 (GPLv3)
 Classifier: Operating System :: OS Independent
 Classifier: Development Status :: 5 - Production/Stable
 Requires-Python: >=3.7
 Description-Content-Type: text/markdown
 Provides-Extra: testing
 Provides-Extra: schemata
 Provides-Extra: journal
diff --git a/swh.storage.egg-info/PKG-INFO b/swh.storage.egg-info/PKG-INFO
index c1816fd8..ef1fa92e 100644
--- a/swh.storage.egg-info/PKG-INFO
+++ b/swh.storage.egg-info/PKG-INFO
@@ -1,216 +1,216 @@
 Metadata-Version: 2.1
 Name: swh.storage
-Version: 0.1.0
+Version: 0.1.1
 Summary: Software Heritage storage manager
 Home-page: https://forge.softwareheritage.org/diffusion/DSTO/
 Author: Software Heritage developers
 Author-email: swh-devel@inria.fr
 License: UNKNOWN
 Project-URL: Bug Reports, https://forge.softwareheritage.org/maniphest
 Project-URL: Funding, https://www.softwareheritage.org/donate
 Project-URL: Source, https://forge.softwareheritage.org/source/swh-storage
 Project-URL: Documentation, https://docs.softwareheritage.org/devel/swh-storage/
 Description: swh-storage
         ===========
         
         Abstraction layer over the archive, allowing to access all stored source code
         artifacts as well as their metadata.
         
         See the
         [documentation](https://docs.softwareheritage.org/devel/swh-storage/index.html)
         for more details.
         
         ## Quick start
         
         ### Dependencies
         
         Python tests for this module include tests that cannot be run without a local
         Postgresql database, so you need the Postgresql server executable on your
         machine (no need to have a running Postgresql server). They also expect a
         cassandra server.
         
         #### Debian-like host
         
         ```
         $ sudo apt install libpq-dev postgresql-11 cassandra
         ```
         
         #### Non Debian-like host
         
         The tests expects `/usr/sbin/cassandra` to exist.
         
         Optionally, you can avoid running the cassandra tests.
         
         ```
         (swh) :~/swh-storage$ tox -- -m 'not cassandra'
         ```
         
         ### Installation
         
         It is strongly recommended to use a virtualenv. In the following, we
         consider you work in a virtualenv named `swh`. See the
         [developer setup guide](https://docs.softwareheritage.org/devel/developer-setup.html#developer-setup)
         for a more details on how to setup a working environment.
         
         
         You can install the package directly from
         [pypi](https://pypi.org/p/swh.storage):
         
         ```
         (swh) :~$ pip install swh.storage
         [...]
         ```
         
         Or from sources:
         
         ```
         (swh) :~$ git clone https://forge.softwareheritage.org/source/swh-storage.git
         [...]
         (swh) :~$ cd swh-storage
         (swh) :~/swh-storage$ pip install .
         [...]
         ```
         
         Then you can check it's properly installed:
         ```
         (swh) :~$ swh storage --help
         Usage: swh storage [OPTIONS] COMMAND [ARGS]...
         
           Software Heritage Storage tools.
         
         Options:
           -h, --help  Show this message and exit.
         
         Commands:
           rpc-serve  Software Heritage Storage RPC server.
         ```
         
         
         ## Tests
         
         The best way of running Python tests for this module is to use
         [tox](https://tox.readthedocs.io/).
         
         ```
         (swh) :~$ pip install tox
         ```
         
         ### tox
         
         From the sources directory, simply use tox:
         
         ```
         (swh) :~/swh-storage$ tox
         [...]
         ========= 315 passed, 6 skipped, 15 warnings in 40.86 seconds ==========
         _______________________________ summary ________________________________
           flake8: commands succeeded
           py3: commands succeeded
           congratulations :)
         ```
         
         ## Development
         
         The storage server can be locally started. It requires a configuration file and
         a running Postgresql database.
         
         ### Sample configuration
         
         A typical configuration `storage.yml` file is:
         
         ```
         storage:
           cls: local
           args:
             db: "dbname=softwareheritage-dev user=<user> password=<pwd>"
             objstorage:
               cls: pathslicing
               args:
                 root: /tmp/swh-storage/
                 slicing: 0:2/2:4/4:6
         ```
         
         which means, this uses:
         
         - a local storage instance whose db connection is to
           `softwareheritage-dev` local instance,
         
         - the objstorage uses a local objstorage instance whose:
         
           - `root` path is /tmp/swh-storage,
         
           - slicing scheme is `0:2/2:4/4:6`. This means that the identifier of
             the content (sha1) which will be stored on disk at first level
             with the first 2 hex characters, the second level with the next 2
             hex characters and the third level with the next 2 hex
             characters. And finally the complete hash file holding the raw
             content. For example: 00062f8bd330715c4f819373653d97b3cd34394c
             will be stored at 00/06/2f/00062f8bd330715c4f819373653d97b3cd34394c
         
         Note that the `root` path should exist on disk before starting the server.
         
         
         ### Starting the storage server
         
         If the python package has been properly installed (e.g. in a virtual env), you
         should be able to use the command:
         
         ```
         (swh) :~/swh-storage$ swh storage rpc-serve storage.yml
         ```
         
         This runs a local swh-storage api at 5002 port.
         
         ```
         (swh) :~/swh-storage$ curl http://127.0.0.1:5002
         <html>
         <head><title>Software Heritage storage server</title></head>
         <body>
         <p>You have reached the
         <a href="https://www.softwareheritage.org/">Software Heritage</a>
         storage server.<br />
         See its
         <a href="https://docs.softwareheritage.org/devel/swh-storage/">documentation
         and API</a> for more information</p>
         ```
         
         ### And then what?
         
         In your upper layer
         ([loader-git](https://forge.softwareheritage.org/source/swh-loader-git/),
         [loader-svn](https://forge.softwareheritage.org/source/swh-loader-svn/),
         etc...), you can define a remote storage with this snippet of yaml
         configuration.
         
         ```
         storage:
           cls: remote
           args:
             url: http://localhost:5002/
         ```
         
         You could directly define a local storage with the following snippet:
         
         ```
         storage:
           cls: local
           args:
             db: service=swh-dev
             objstorage:
               cls: pathslicing
               args:
                 root: /home/storage/swh-storage/
                 slicing: 0:2/2:4/4:6
         ```
         
 Platform: UNKNOWN
 Classifier: Programming Language :: Python :: 3
 Classifier: Intended Audience :: Developers
 Classifier: License :: OSI Approved :: GNU General Public License v3 (GPLv3)
 Classifier: Operating System :: OS Independent
 Classifier: Development Status :: 5 - Production/Stable
 Requires-Python: >=3.7
 Description-Content-Type: text/markdown
 Provides-Extra: testing
 Provides-Extra: schemata
 Provides-Extra: journal
diff --git a/swh/storage/tests/algos/test_snapshot.py b/swh/storage/tests/algos/test_snapshot.py
index 912fb4c2..7e7bafc9 100644
--- a/swh/storage/tests/algos/test_snapshot.py
+++ b/swh/storage/tests/algos/test_snapshot.py
@@ -1,36 +1,44 @@
 # Copyright (C) 2018  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 from hypothesis import given
+import pytest
 
 from swh.model.identifiers import snapshot_identifier, identifier_to_bytes
 from swh.model.hypothesis_strategies import snapshots, branch_names, branch_targets
 
 from swh.storage.algos.snapshot import snapshot_get_all_branches
-from swh.storage.tests.test_in_memory import swh_storage_backend_config  # noqa
+
+
+@pytest.fixture
+def swh_storage_backend_config():
+    yield {
+        "cls": "memory",
+        "journal_writer": None,
+    }
 
 
 @given(snapshot=snapshots(min_size=0, max_size=10, only_objects=False))
 def test_snapshot_small(swh_storage, snapshot):  # noqa
     snapshot = snapshot.to_dict()
     swh_storage.snapshot_add([snapshot])
 
     returned_snapshot = snapshot_get_all_branches(swh_storage, snapshot["id"])
     assert snapshot == returned_snapshot
 
 
 @given(branch_name=branch_names(), branch_target=branch_targets(only_objects=True))
 def test_snapshot_large(swh_storage, branch_name, branch_target):  # noqa
     branch_target = branch_target.to_dict()
 
     snapshot = {
         "branches": {b"%s%05d" % (branch_name, i): branch_target for i in range(10000)}
     }
     snapshot["id"] = identifier_to_bytes(snapshot_identifier(snapshot))
 
     swh_storage.snapshot_add([snapshot])
 
     returned_snapshot = snapshot_get_all_branches(swh_storage, snapshot["id"])
     assert snapshot == returned_snapshot
diff --git a/version.txt b/version.txt
index 22ba6855..518279ab 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-v0.1.0-0-gf9b2ca3
\ No newline at end of file
+v0.1.1-0-g25f584f
\ No newline at end of file