diff --git a/docs/conf.py b/docs/conf.py
index 3256549..bff92da 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -8,32 +8,32 @@
 
 from importlib.metadata import version as get_version
 
-project = 'WuttaMess'
-copyright = '2024, Lance Edgar'
-author = 'Lance Edgar'
-release = get_version('WuttaMess')
+project = "WuttaMess"
+copyright = "2024, Lance Edgar"
+author = "Lance Edgar"
+release = get_version("WuttaMess")
 
 # -- General configuration ---------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
 
 extensions = [
-    'sphinx.ext.autodoc',
-    'sphinx.ext.intersphinx',
-    'sphinx.ext.viewcode',
-    'sphinx.ext.todo',
+    "sphinx.ext.autodoc",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.viewcode",
+    "sphinx.ext.todo",
 ]
 
-templates_path = ['_templates']
-exclude_patterns = ['_build', 'Thumbs.db', '.DS_Store']
+templates_path = ["_templates"]
+exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
 intersphinx_mapping = {
-    'fabsync': ('https://fabsync.ignorare.dev/', None),
-    'invoke': ('https://docs.pyinvoke.org/en/stable/', None),
+    "fabsync": ("https://fabsync.ignorare.dev/", None),
+    "invoke": ("https://docs.pyinvoke.org/en/stable/", None),
 }
 
 
 # -- Options for HTML output -------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-html-output
 
-html_theme = 'furo'
-html_static_path = ['_static']
+html_theme = "furo"
+html_static_path = ["_static"]
diff --git a/src/wuttamess/_version.py b/src/wuttamess/_version.py
index c3d9e4f..96c91a0 100644
--- a/src/wuttamess/_version.py
+++ b/src/wuttamess/_version.py
@@ -3,4 +3,4 @@
 from importlib.metadata import version
 
 
-__version__ = version('WuttaMess')
+__version__ = version("WuttaMess")
diff --git a/src/wuttamess/apt.py b/src/wuttamess/apt.py
index e11dca2..df584a4 100644
--- a/src/wuttamess/apt.py
+++ b/src/wuttamess/apt.py
@@ -25,7 +25,7 @@ APT package management
 """
 
 
-def dist_upgrade(c, frontend='noninteractive'):
+def dist_upgrade(c, frontend="noninteractive"):
     """
     Run a full dist-upgrade for APT.  Essentially this runs:
 
@@ -46,9 +46,9 @@ def install(c, *packages, **kwargs):
 
        apt install PKG [PKG ...]
     """
-    frontend = kwargs.pop('frontend', 'noninteractive')
-    packages = ' '.join(packages)
-    return c.run(f'DEBIAN_FRONTEND={frontend} apt-get --assume-yes install {packages}')
+    frontend = kwargs.pop("frontend", "noninteractive")
+    packages = " ".join(packages)
+    return c.run(f"DEBIAN_FRONTEND={frontend} apt-get --assume-yes install {packages}")
 
 
 def is_installed(c, package):
@@ -61,7 +61,7 @@ def is_installed(c, package):
 
     :returns: ``True`` if package is installed, else ``False``.
     """
-    return c.run(f'dpkg-query -s {package}', warn=True).ok
+    return c.run(f"dpkg-query -s {package}", warn=True).ok
 
 
 def update(c):
@@ -72,10 +72,10 @@ def update(c):
 
        apt update
     """
-    c.run('apt-get update')
+    c.run("apt-get update")
 
 
-def upgrade(c, dist_upgrade=False, frontend='noninteractive'):
+def upgrade(c, dist_upgrade=False, frontend="noninteractive"):
     """
     Upgrade packages via APT.  Essentially this runs:
 
@@ -87,8 +87,8 @@ def upgrade(c, dist_upgrade=False, frontend='noninteractive'):
 
        apt dist-upgrade
     """
-    options = ''
-    if frontend == 'noninteractive':
+    options = ""
+    if frontend == "noninteractive":
         options = '--option Dpkg::Options::="--force-confdef" --option Dpkg::Options::="--force-confold"'
-    upgrade = 'dist-upgrade' if dist_upgrade else 'upgrade'
-    c.run(f'DEBIAN_FRONTEND={frontend} apt-get --assume-yes {options} {upgrade}')
+    upgrade = "dist-upgrade" if dist_upgrade else "upgrade"
+    c.run(f"DEBIAN_FRONTEND={frontend} apt-get --assume-yes {options} {upgrade}")
diff --git a/src/wuttamess/postfix.py b/src/wuttamess/postfix.py
index e5e9730..d6ef4b9 100644
--- a/src/wuttamess/postfix.py
+++ b/src/wuttamess/postfix.py
@@ -36,32 +36,32 @@ def set_myhostname(c, hostname):
     """
     Configure the ``myhostname`` setting with the given string.
     """
-    set_config(c, 'myhostname', hostname)
+    set_config(c, "myhostname", hostname)
 
 
 def set_myorigin(c, origin):
     """
     Configure the ``myorigin`` setting with the given string.
     """
-    set_config(c, 'myorigin', origin)
+    set_config(c, "myorigin", origin)
 
 
 def set_mydestination(c, *destinations):
     """
     Configure the ``mydestinations`` setting with the given strings.
     """
-    set_config(c, 'mydestination', ', '.join(destinations))
+    set_config(c, "mydestination", ", ".join(destinations))
 
 
 def set_mynetworks(c, *networks):
     """
     Configure the ``mynetworks`` setting with the given strings.
     """
-    set_config(c, 'mynetworks', ' '.join(networks))
+    set_config(c, "mynetworks", " ".join(networks))
 
 
 def set_relayhost(c, relayhost):
     """
     Configure the ``relayhost`` setting with the given string
     """
-    set_config(c, 'relayhost', relayhost)
+    set_config(c, "relayhost", relayhost)
diff --git a/src/wuttamess/postgres.py b/src/wuttamess/postgres.py
index 1317768..8416a58 100644
--- a/src/wuttamess/postgres.py
+++ b/src/wuttamess/postgres.py
@@ -25,7 +25,7 @@ PostgreSQL DB utilities
 """
 
 
-def sql(c, sql, database='', port=None, **kwargs):
+def sql(c, sql, database="", port=None, **kwargs):
     """
     Execute some SQL as the ``postgres`` user.
 
@@ -38,9 +38,12 @@ def sql(c, sql, database='', port=None, **kwargs):
 
     :param port: Optional port for PostgreSQL; default is 5432.
     """
-    port = f' --port={port}' if port else ''
-    return c.sudo(f'psql{port} --tuples-only --no-align --command="{sql}" {database}',
-                  user='postgres', **kwargs)
+    port = f" --port={port}" if port else ""
+    return c.sudo(
+        f'psql{port} --tuples-only --no-align --command="{sql}" {database}',
+        user="postgres",
+        **kwargs,
+    )
 
 
 def user_exists(c, name, port=None):
@@ -55,7 +58,9 @@ def user_exists(c, name, port=None):
 
     :returns: ``True`` if user exists, else ``False``.
     """
-    user = sql(c, f"SELECT rolname FROM pg_roles WHERE rolname = '{name}'", port=port).stdout.strip()
+    user = sql(
+        c, f"SELECT rolname FROM pg_roles WHERE rolname = '{name}'", port=port
+    ).stdout.strip()
     return bool(user)
 
 
@@ -77,9 +82,11 @@ def create_user(c, name, password=None, port=None, checkfirst=True):
        try to create user with no check.
     """
     if not checkfirst or not user_exists(c, name, port=port):
-        portarg = f' --port={port}' if port else ''
-        c.sudo(f'createuser{portarg} --no-createrole --no-superuser {name}',
-               user='postgres')
+        portarg = f" --port={port}" if port else ""
+        c.sudo(
+            f"createuser{portarg} --no-createrole --no-superuser {name}",
+            user="postgres",
+        )
         if password:
             set_user_password(c, name, password, port=port)
 
@@ -96,7 +103,13 @@ def set_user_password(c, name, password, port=None):
 
     :param port: Optional port for PostgreSQL; default is 5432.
     """
-    sql(c, f"ALTER USER \\\"{name}\\\" PASSWORD '{password}';", port=port, hide=True, echo=False)
+    sql(
+        c,
+        f"ALTER USER \\\"{name}\\\" PASSWORD '{password}';",
+        port=port,
+        hide=True,
+        echo=False,
+    )
 
 
 def db_exists(c, name, port=None):
@@ -111,7 +124,9 @@ def db_exists(c, name, port=None):
 
     :returns: ``True`` if database exists, else ``False``.
     """
-    db = sql(c, f"SELECT datname FROM pg_database WHERE datname = '{name}'", port=port).stdout.strip()
+    db = sql(
+        c, f"SELECT datname FROM pg_database WHERE datname = '{name}'", port=port
+    ).stdout.strip()
     return db == name
 
 
@@ -132,10 +147,9 @@ def create_db(c, name, owner=None, port=None, checkfirst=True):
        create DB with no check.
     """
     if not checkfirst or not db_exists(c, name, port=port):
-        port = f' --port={port}' if port else ''
-        owner = f' --owner={owner}' if owner else ''
-        c.sudo(f'createdb{port}{owner} {name}',
-               user='postgres')
+        port = f" --port={port}" if port else ""
+        owner = f" --owner={owner}" if owner else ""
+        c.sudo(f"createdb{port}{owner} {name}", user="postgres")
 
 
 def drop_db(c, name, checkfirst=True):
@@ -151,7 +165,7 @@ def drop_db(c, name, checkfirst=True):
        DB with no check.
     """
     if not checkfirst or db_exists(c, name):
-        c.sudo(f'dropdb {name}', user='postgres')
+        c.sudo(f"dropdb {name}", user="postgres")
 
 
 def dump_db(c, name):
@@ -170,15 +184,15 @@ def dump_db(c, name):
        filename and not the path, since the file is expected to exist
        in the connected user's home folder.
     """
-    sql_name = f'{name}.sql'
-    gz_name = f'{sql_name}.gz'
-    tmp_name = f'/tmp/{gz_name}'
+    sql_name = f"{name}.sql"
+    gz_name = f"{sql_name}.gz"
+    tmp_name = f"/tmp/{gz_name}"
 
     # TODO: when pg_dump fails the command still succeeds!  (would this work?)
-    #cmd = f'set -e && pg_dump {name} | gzip -c > {tmp_name}'
-    cmd = f'pg_dump {name} | gzip -c > {tmp_name}'
+    # cmd = f'set -e && pg_dump {name} | gzip -c > {tmp_name}'
+    cmd = f"pg_dump {name} | gzip -c > {tmp_name}"
 
-    c.sudo(cmd, user='postgres')
+    c.sudo(cmd, user="postgres")
     c.run(f"cp {tmp_name} {gz_name}")
     c.run(f"rm {tmp_name}")
 
diff --git a/src/wuttamess/ssh.py b/src/wuttamess/ssh.py
index 87a7540..89a2b64 100644
--- a/src/wuttamess/ssh.py
+++ b/src/wuttamess/ssh.py
@@ -46,11 +46,11 @@ def cache_host_key(c, host, port=None, user=None):
     :param user: User on the fabric target whose SSH key cache should
        be updated to include the given ``host``.
     """
-    port = f'-p {port} ' if port else ''
+    port = f"-p {port} " if port else ""
 
     # first try to run a basic command over ssh
-    cmd = f'ssh {port}{host} whoami'
-    if user and user != 'root':
+    cmd = f"ssh {port}{host} whoami"
+    if user and user != "root":
         result = c.sudo(cmd, user=user, warn=True)
     else:
         result = c.run(cmd, warn=True)
@@ -68,8 +68,8 @@ def cache_host_key(c, host, port=None, user=None):
     # okay then we now think that the ssh connection itself
     # was not made, which presumably means we *do* need to
     # cache the host key, so try that now
-    cmd = f'ssh -o StrictHostKeyChecking=no {port}{host} whoami'
-    if user and user != 'root':
+    cmd = f"ssh -o StrictHostKeyChecking=no {port}{host} whoami"
+    if user and user != "root":
         c.sudo(cmd, user=user, warn=True)
     else:
         c.run(cmd, warn=True)
diff --git a/src/wuttamess/sync.py b/src/wuttamess/sync.py
index 6147ca7..24b9165 100644
--- a/src/wuttamess/sync.py
+++ b/src/wuttamess/sync.py
@@ -29,7 +29,7 @@ See :doc:`/narr/usage` for a basic example.
 import fabsync
 
 
-def make_root(path, dest='/'):
+def make_root(path, dest="/"):
     """
     Make and return a "root" object for use with future sync calls.
 
@@ -91,9 +91,9 @@ def isync(c, root, selector=None, tags=None, echo=True, **kwargs):
         if not isinstance(selector, fabsync.ItemSelector):
             kw = {}
             if tags:
-                kw['tags'] = tags
+                kw["tags"] = tags
             selector = make_selector(selector, **kw)
-        kwargs['selector'] = selector
+        kwargs["selector"] = selector
 
     for result in fabsync.isync(c, root, **kwargs):
         if echo:
@@ -111,5 +111,4 @@ def check_isync(c, root, selector=None, **kwargs):
     :returns: ``True`` if any sync result indicates a file was
        modified; otherwise ``False``.
     """
-    return any([result.modified
-                for result in isync(c, root, selector, **kwargs)])
+    return any([result.modified for result in isync(c, root, selector, **kwargs)])
diff --git a/src/wuttamess/util.py b/src/wuttamess/util.py
index 2fde609..e201c3e 100644
--- a/src/wuttamess/util.py
+++ b/src/wuttamess/util.py
@@ -34,7 +34,7 @@ def exists(c, path):
     """
     Returns ``True`` if given path exists on the host, otherwise ``False``.
     """
-    return not c.run(f'test -e {path}', warn=True).failed
+    return not c.run(f"test -e {path}", warn=True).failed
 
 
 def get_home_path(c, user=None):
@@ -49,8 +49,8 @@ def get_home_path(c, user=None):
     :returns: Home folder path as string.
     """
     user = user or c.user
-    home = c.run(f'getent passwd {user} | cut -d: -f6').stdout.strip()
-    home = home.rstrip('/')
+    home = c.run(f"getent passwd {user} | cut -d: -f6").stdout.strip()
+    home = home.rstrip("/")
     return home
 
 
@@ -96,6 +96,7 @@ def mako_renderer(c, env={}):
 
            sync.check_isync(c, root, 'etc/postfix', renderers=renderers)
     """
+
     def render(path: Path, vars: Mapping[str, Any], **kwargs) -> bytes:
         return Template(filename=str(path)).render(**env)
 
@@ -113,7 +114,7 @@ def set_timezone(c, timezone):
     """
     c.run(f"bash -c 'echo {timezone} > /etc/timezone'")
 
-    if is_symlink(c, '/etc/localtime'):
-        c.run(f'ln -sf /usr/share/zoneinfo/{timezone} /etc/localtime')
+    if is_symlink(c, "/etc/localtime"):
+        c.run(f"ln -sf /usr/share/zoneinfo/{timezone} /etc/localtime")
     else:
-        c.run(f'cp /usr/share/zoneinfo/{timezone} /etc/localtime')
+        c.run(f"cp /usr/share/zoneinfo/{timezone} /etc/localtime")
diff --git a/src/wuttamess/wutta.py b/src/wuttamess/wutta.py
index 0145542..3688e53 100644
--- a/src/wuttamess/wutta.py
+++ b/src/wuttamess/wutta.py
@@ -27,7 +27,7 @@ Utilities for Wutta Framework
 from wuttamess import postgres
 
 
-def purge_email_settings(c, dbname, appname='wutta'):
+def purge_email_settings(c, dbname, appname="wutta"):
     """
     Purge production email settings for a database.
 
@@ -47,11 +47,23 @@ def purge_email_settings(c, dbname, appname='wutta'):
 
     :param appname: The ``appname`` used to determine setting names.
     """
-    postgres.sql(c, f"delete from setting where name like '{appname}.email.%.sender';",
-                 database=dbname)
-    postgres.sql(c, f"delete from setting where name like '{appname}.email.%.to';",
-                 database=dbname)
-    postgres.sql(c, f"delete from setting where name like '{appname}.email.%.cc';",
-                 database=dbname)
-    postgres.sql(c, f"delete from setting where name like '{appname}.email.%.bcc';",
-                 database=dbname)
+    postgres.sql(
+        c,
+        f"delete from setting where name like '{appname}.email.%.sender';",
+        database=dbname,
+    )
+    postgres.sql(
+        c,
+        f"delete from setting where name like '{appname}.email.%.to';",
+        database=dbname,
+    )
+    postgres.sql(
+        c,
+        f"delete from setting where name like '{appname}.email.%.cc';",
+        database=dbname,
+    )
+    postgres.sql(
+        c,
+        f"delete from setting where name like '{appname}.email.%.bcc';",
+        database=dbname,
+    )
diff --git a/tasks.py b/tasks.py
index facdf57..49daeb4 100644
--- a/tasks.py
+++ b/tasks.py
@@ -15,10 +15,10 @@ def release(c, skip_tests=False):
     Release a new version of WuttaMess
     """
     if not skip_tests:
-        c.run('pytest')
+        c.run("pytest")
 
-    if os.path.exists('dist'):
-        shutil.rmtree('dist')
+    if os.path.exists("dist"):
+        shutil.rmtree("dist")
 
-    c.run('python -m build --sdist')
-    c.run('twine upload dist/*')
+    c.run("python -m build --sdist")
+    c.run("twine upload dist/*")
diff --git a/tests/test_apt.py b/tests/test_apt.py
index 50c80a9..367ce05 100644
--- a/tests/test_apt.py
+++ b/tests/test_apt.py
@@ -10,19 +10,23 @@ class TestDistUpgrade(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        with patch.object(mod, 'update') as update:
-            with patch.object(mod, 'upgrade') as upgrade:
-                mod.dist_upgrade(c, frontend='whatever')
+        with patch.object(mod, "update") as update:
+            with patch.object(mod, "upgrade") as upgrade:
+                mod.dist_upgrade(c, frontend="whatever")
                 update.assert_called_once_with(c)
-                upgrade.assert_called_once_with(c, dist_upgrade=True, frontend='whatever')
+                upgrade.assert_called_once_with(
+                    c, dist_upgrade=True, frontend="whatever"
+                )
 
 
 class TestInstall(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.install(c, 'postfix')
-        c.run.assert_called_once_with('DEBIAN_FRONTEND=noninteractive apt-get --assume-yes install postfix')
+        mod.install(c, "postfix")
+        c.run.assert_called_once_with(
+            "DEBIAN_FRONTEND=noninteractive apt-get --assume-yes install postfix"
+        )
 
 
 class TestIsInstalled(TestCase):
@@ -30,14 +34,14 @@ class TestIsInstalled(TestCase):
     def test_already_installed(self):
         c = MagicMock()
         c.run.return_value.ok = True
-        self.assertTrue(mod.is_installed(c, 'postfix'))
-        c.run.assert_called_once_with('dpkg-query -s postfix', warn=True)
+        self.assertTrue(mod.is_installed(c, "postfix"))
+        c.run.assert_called_once_with("dpkg-query -s postfix", warn=True)
 
     def test_not_installed(self):
         c = MagicMock()
         c.run.return_value.ok = False
-        self.assertFalse(mod.is_installed(c, 'postfix'))
-        c.run.assert_called_once_with('dpkg-query -s postfix', warn=True)
+        self.assertFalse(mod.is_installed(c, "postfix"))
+        c.run.assert_called_once_with("dpkg-query -s postfix", warn=True)
 
 
 class TestUpdate(TestCase):
@@ -45,7 +49,7 @@ class TestUpdate(TestCase):
     def test_basic(self):
         c = MagicMock()
         mod.update(c)
-        c.run.assert_called_once_with('apt-get update')
+        c.run.assert_called_once_with("apt-get update")
 
 
 class TestUpgrade(TestCase):
@@ -53,4 +57,6 @@ class TestUpgrade(TestCase):
     def test_basic(self):
         c = MagicMock()
         mod.upgrade(c)
-        c.run.assert_called_once_with('DEBIAN_FRONTEND=noninteractive apt-get --assume-yes --option Dpkg::Options::="--force-confdef" --option Dpkg::Options::="--force-confold" upgrade')
+        c.run.assert_called_once_with(
+            'DEBIAN_FRONTEND=noninteractive apt-get --assume-yes --option Dpkg::Options::="--force-confdef" --option Dpkg::Options::="--force-confold" upgrade'
+        )
diff --git a/tests/test_postfix.py b/tests/test_postfix.py
index 1f75253..86e01b1 100644
--- a/tests/test_postfix.py
+++ b/tests/test_postfix.py
@@ -10,7 +10,7 @@ class TestSetConfig(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.set_config(c, 'foo', 'bar')
+        mod.set_config(c, "foo", "bar")
         c.run.assert_called_once_with("postconf -e 'foo=bar'")
 
 
@@ -18,7 +18,7 @@ class TestSetMyhostname(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.set_myhostname(c, 'test.example.com')
+        mod.set_myhostname(c, "test.example.com")
         c.run.assert_called_once_with("postconf -e 'myhostname=test.example.com'")
 
 
@@ -26,7 +26,7 @@ class TestSetMyorigin(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.set_myorigin(c, 'example.com')
+        mod.set_myorigin(c, "example.com")
         c.run.assert_called_once_with("postconf -e 'myorigin=example.com'")
 
 
@@ -34,15 +34,17 @@ class TestSetMydestination(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.set_mydestination(c, 'example.com', 'test.example.com', 'localhost')
-        c.run.assert_called_once_with("postconf -e 'mydestination=example.com, test.example.com, localhost'")
+        mod.set_mydestination(c, "example.com", "test.example.com", "localhost")
+        c.run.assert_called_once_with(
+            "postconf -e 'mydestination=example.com, test.example.com, localhost'"
+        )
 
 
 class TestSetMynetworks(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.set_mynetworks(c, '127.0.0.0/8', '[::1]/128')
+        mod.set_mynetworks(c, "127.0.0.0/8", "[::1]/128")
         c.run.assert_called_once_with("postconf -e 'mynetworks=127.0.0.0/8 [::1]/128'")
 
 
@@ -50,5 +52,5 @@ class TestSetRelayhost(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.set_relayhost(c, 'mail.example.com')
+        mod.set_relayhost(c, "mail.example.com")
         c.run.assert_called_once_with("postconf -e 'relayhost=mail.example.com'")
diff --git a/tests/test_postgres.py b/tests/test_postgres.py
index 95e49b4..bfe59a7 100644
--- a/tests/test_postgres.py
+++ b/tests/test_postgres.py
@@ -11,98 +11,115 @@ class TestSql(TestCase):
     def test_basic(self):
         c = MagicMock()
         mod.sql(c, "select @@version")
-        c.sudo.assert_called_once_with('psql --tuples-only --no-align --command="select @@version" ',
-                                       user='postgres')
+        c.sudo.assert_called_once_with(
+            'psql --tuples-only --no-align --command="select @@version" ',
+            user="postgres",
+        )
 
 
 class TestUserExists(TestCase):
 
     def test_user_exists(self):
         c = MagicMock()
-        with patch.object(mod, 'sql') as sql:
-            sql.return_value.stdout = 'foo'
-            self.assertTrue(mod.user_exists(c, 'foo'))
-            sql.assert_called_once_with(c, "SELECT rolname FROM pg_roles WHERE rolname = 'foo'", port=None)
+        with patch.object(mod, "sql") as sql:
+            sql.return_value.stdout = "foo"
+            self.assertTrue(mod.user_exists(c, "foo"))
+            sql.assert_called_once_with(
+                c, "SELECT rolname FROM pg_roles WHERE rolname = 'foo'", port=None
+            )
 
     def test_user_does_not_exist(self):
         c = MagicMock()
-        with patch.object(mod, 'sql') as sql:
-            sql.return_value.stdout = ''
-            self.assertFalse(mod.user_exists(c, 'foo'))
-            sql.assert_called_once_with(c, "SELECT rolname FROM pg_roles WHERE rolname = 'foo'", port=None)
+        with patch.object(mod, "sql") as sql:
+            sql.return_value.stdout = ""
+            self.assertFalse(mod.user_exists(c, "foo"))
+            sql.assert_called_once_with(
+                c, "SELECT rolname FROM pg_roles WHERE rolname = 'foo'", port=None
+            )
 
 
 class TestCreateUser(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        with patch.object(mod, 'set_user_password') as set_user_password:
-            mod.create_user(c, 'foo', checkfirst=False)
-            c.sudo.assert_called_once_with('createuser --no-createrole --no-superuser foo',
-                                           user='postgres')
+        with patch.object(mod, "set_user_password") as set_user_password:
+            mod.create_user(c, "foo", checkfirst=False)
+            c.sudo.assert_called_once_with(
+                "createuser --no-createrole --no-superuser foo", user="postgres"
+            )
             set_user_password.assert_not_called()
 
     def test_user_exists(self):
         c = MagicMock()
 
-        with patch.object(mod, 'user_exists') as user_exists:
+        with patch.object(mod, "user_exists") as user_exists:
             user_exists.return_value = True
 
-            mod.create_user(c, 'foo')
-            user_exists.assert_called_once_with(c, 'foo', port=None)
+            mod.create_user(c, "foo")
+            user_exists.assert_called_once_with(c, "foo", port=None)
             c.sudo.assert_not_called()
 
     def test_with_password(self):
         c = MagicMock()
-        with patch.object(mod, 'set_user_password') as set_user_password:
-            mod.create_user(c, 'foo', 'foopass', checkfirst=False)
-            c.sudo.assert_called_once_with('createuser --no-createrole --no-superuser foo',
-                                           user='postgres')
-            set_user_password.assert_called_once_with(c, 'foo', 'foopass', port=None)
+        with patch.object(mod, "set_user_password") as set_user_password:
+            mod.create_user(c, "foo", "foopass", checkfirst=False)
+            c.sudo.assert_called_once_with(
+                "createuser --no-createrole --no-superuser foo", user="postgres"
+            )
+            set_user_password.assert_called_once_with(c, "foo", "foopass", port=None)
 
 
 class TestSetUserPassword(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        with patch.object(mod, 'sql') as sql:
-            mod.set_user_password(c, 'foo', 'foopass')
-            sql.assert_called_once_with(c, "ALTER USER \\\"foo\\\" PASSWORD 'foopass';",
-                                        port=None, hide=True, echo=False)
+        with patch.object(mod, "sql") as sql:
+            mod.set_user_password(c, "foo", "foopass")
+            sql.assert_called_once_with(
+                c,
+                "ALTER USER \\\"foo\\\" PASSWORD 'foopass';",
+                port=None,
+                hide=True,
+                echo=False,
+            )
 
 
 class TestDbExists(TestCase):
 
     def test_db_exists(self):
         c = MagicMock()
-        with patch.object(mod, 'sql') as sql:
-            sql.return_value.stdout = 'foo'
-            self.assertTrue(mod.db_exists(c, 'foo'))
-            sql.assert_called_once_with(c, "SELECT datname FROM pg_database WHERE datname = 'foo'", port=None)
+        with patch.object(mod, "sql") as sql:
+            sql.return_value.stdout = "foo"
+            self.assertTrue(mod.db_exists(c, "foo"))
+            sql.assert_called_once_with(
+                c, "SELECT datname FROM pg_database WHERE datname = 'foo'", port=None
+            )
 
     def test_db_does_not_exist(self):
         c = MagicMock()
-        with patch.object(mod, 'sql') as sql:
-            sql.return_value.stdout = ''
-            self.assertFalse(mod.db_exists(c, 'foo'))
-            sql.assert_called_once_with(c, "SELECT datname FROM pg_database WHERE datname = 'foo'", port=None)
+        with patch.object(mod, "sql") as sql:
+            sql.return_value.stdout = ""
+            self.assertFalse(mod.db_exists(c, "foo"))
+            sql.assert_called_once_with(
+                c, "SELECT datname FROM pg_database WHERE datname = 'foo'", port=None
+            )
 
 
 class TestCreateDb(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.create_db(c, 'foo', checkfirst=False)
-        c.sudo.assert_called_once_with('createdb foo', user='postgres')
+        mod.create_db(c, "foo", checkfirst=False)
+        c.sudo.assert_called_once_with("createdb foo", user="postgres")
 
     def test_db_exists(self):
         c = MagicMock()
 
-        with patch.object(mod, 'db_exists') as db_exists:
+        with patch.object(mod, "db_exists") as db_exists:
             db_exists.return_value = True
 
-            mod.create_db(c, 'foo')
-            db_exists.assert_called_once_with(c, 'foo', port=None)
+            mod.create_db(c, "foo")
+            db_exists.assert_called_once_with(c, "foo", port=None)
             c.sudo.assert_not_called()
 
 
@@ -110,17 +127,17 @@ class TestDropDb(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.drop_db(c, 'foo', checkfirst=False)
-        c.sudo.assert_called_once_with('dropdb foo', user='postgres')
+        mod.drop_db(c, "foo", checkfirst=False)
+        c.sudo.assert_called_once_with("dropdb foo", user="postgres")
 
     def test_db_does_not_exist(self):
         c = MagicMock()
 
-        with patch.object(mod, 'db_exists') as db_exists:
+        with patch.object(mod, "db_exists") as db_exists:
             db_exists.return_value = False
 
-            mod.drop_db(c, 'foo')
-            db_exists.assert_called_once_with(c, 'foo')
+            mod.drop_db(c, "foo")
+            db_exists.assert_called_once_with(c, "foo")
             c.sudo.assert_not_called()
 
 
@@ -128,7 +145,9 @@ class TestDumpDb(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        result = mod.dump_db(c, 'foo')
-        self.assertEqual(result, 'foo.sql.gz')
-        c.sudo.assert_called_once_with('pg_dump foo | gzip -c > /tmp/foo.sql.gz', user='postgres')
-        c.run.assert_called_with('rm /tmp/foo.sql.gz')
+        result = mod.dump_db(c, "foo")
+        self.assertEqual(result, "foo.sql.gz")
+        c.sudo.assert_called_once_with(
+            "pg_dump foo | gzip -c > /tmp/foo.sql.gz", user="postgres"
+        )
+        c.run.assert_called_with("rm /tmp/foo.sql.gz")
diff --git a/tests/test_ssh.py b/tests/test_ssh.py
index 93b1cdc..bee1574 100644
--- a/tests/test_ssh.py
+++ b/tests/test_ssh.py
@@ -13,8 +13,8 @@ class TestCacheHostKey(TestCase):
 
         # assume the first command runs okay
         c.run.return_value.failed = False
-        mod.cache_host_key(c, 'example.com')
-        c.run.assert_called_once_with('ssh example.com whoami', warn=True)
+        mod.cache_host_key(c, "example.com")
+        c.run.assert_called_once_with("ssh example.com whoami", warn=True)
 
     def test_root_commands_not_allowed(self):
         c = MagicMock()
@@ -22,25 +22,27 @@ class TestCacheHostKey(TestCase):
         # assume the first command fails b/c "disallowed"
         c.run.return_value.failed = True
         c.run.return_value.stderr = "Disallowed command"
-        mod.cache_host_key(c, 'example.com')
-        c.run.assert_called_once_with('ssh example.com whoami', warn=True)
+        mod.cache_host_key(c, "example.com")
+        c.run.assert_called_once_with("ssh example.com whoami", warn=True)
 
     def test_root_cache_key(self):
         c = MagicMock()
 
         # first command fails; second command caches host key
         c.run.return_value.failed = True
-        mod.cache_host_key(c, 'example.com')
-        c.run.assert_has_calls([call('ssh example.com whoami', warn=True)])
-        c.run.assert_called_with('ssh -o StrictHostKeyChecking=no example.com whoami', warn=True)
+        mod.cache_host_key(c, "example.com")
+        c.run.assert_has_calls([call("ssh example.com whoami", warn=True)])
+        c.run.assert_called_with(
+            "ssh -o StrictHostKeyChecking=no example.com whoami", warn=True
+        )
 
     def test_user_already_cached(self):
         c = MagicMock()
 
         # assume the first command runs okay
         c.sudo.return_value.failed = False
-        mod.cache_host_key(c, 'example.com', user='foo')
-        c.sudo.assert_called_once_with('ssh example.com whoami', user='foo', warn=True)
+        mod.cache_host_key(c, "example.com", user="foo")
+        c.sudo.assert_called_once_with("ssh example.com whoami", user="foo", warn=True)
 
     def test_user_commands_not_allowed(self):
         c = MagicMock()
@@ -48,15 +50,16 @@ class TestCacheHostKey(TestCase):
         # assume the first command fails b/c "disallowed"
         c.sudo.return_value.failed = True
         c.sudo.return_value.stderr = "Disallowed command"
-        mod.cache_host_key(c, 'example.com', user='foo')
-        c.sudo.assert_called_once_with('ssh example.com whoami', user='foo', warn=True)
+        mod.cache_host_key(c, "example.com", user="foo")
+        c.sudo.assert_called_once_with("ssh example.com whoami", user="foo", warn=True)
 
     def test_user_cache_key(self):
         c = MagicMock()
 
         # first command fails; second command caches host key
         c.sudo.return_value.failed = True
-        mod.cache_host_key(c, 'example.com', user='foo')
-        c.sudo.assert_has_calls([call('ssh example.com whoami', user='foo', warn=True)])
-        c.sudo.assert_called_with('ssh -o StrictHostKeyChecking=no example.com whoami',
-                                  user='foo', warn=True)
+        mod.cache_host_key(c, "example.com", user="foo")
+        c.sudo.assert_has_calls([call("ssh example.com whoami", user="foo", warn=True)])
+        c.sudo.assert_called_with(
+            "ssh -o StrictHostKeyChecking=no example.com whoami", user="foo", warn=True
+        )
diff --git a/tests/test_sync.py b/tests/test_sync.py
index 0a11084..8d91a05 100644
--- a/tests/test_sync.py
+++ b/tests/test_sync.py
@@ -12,26 +12,26 @@ from wuttamess import sync as mod
 class TestMakeRoot(TestCase):
 
     def test_basic(self):
-        root = mod.make_root('files')
+        root = mod.make_root("files")
         self.assertIsInstance(root, SyncedRoot)
-        self.assertEqual(root.src, Path('files'))
-        self.assertEqual(root.dest, Path('/'))
+        self.assertEqual(root.src, Path("files"))
+        self.assertEqual(root.dest, Path("/"))
 
 
 class TestMakeSelector(TestCase):
 
     def test_basic(self):
-        selector = mod.make_selector('etc/postfix')
+        selector = mod.make_selector("etc/postfix")
         self.assertIsInstance(selector, ItemSelector)
-        self.assertEqual(selector.subpath, Path('etc/postfix'))
+        self.assertEqual(selector.subpath, Path("etc/postfix"))
 
 
 class TestIsync(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        root = mod.make_root('files')
-        with patch.object(mod, 'fabsync') as fabsync:
+        root = mod.make_root("files")
+        with patch.object(mod, "fabsync") as fabsync:
             fabsync.ItemSelector = ItemSelector
 
             # nothing to sync
@@ -42,7 +42,7 @@ class TestIsync(TestCase):
 
             # sync one file
             fabsync.isync.reset_mock()
-            result = MagicMock(path='/foo', modified=True)
+            result = MagicMock(path="/foo", modified=True)
             fabsync.isync.return_value = [result]
             results = list(mod.isync(c, root))
             self.assertEqual(results, [result])
@@ -50,34 +50,38 @@ class TestIsync(TestCase):
 
             # sync with selector (subpath)
             fabsync.isync.reset_mock()
-            result = MagicMock(path='/foo', modified=True)
+            result = MagicMock(path="/foo", modified=True)
             fabsync.isync.return_value = [result]
-            results = list(mod.isync(c, root, 'foo'))
+            results = list(mod.isync(c, root, "foo"))
             self.assertEqual(results, [result])
-            fabsync.isync.assert_called_once_with(c, root, selector=fabsync.ItemSelector.new('foo'))
+            fabsync.isync.assert_called_once_with(
+                c, root, selector=fabsync.ItemSelector.new("foo")
+            )
 
             # sync with selector (subpath + tags)
             fabsync.isync.reset_mock()
-            result = MagicMock(path='/foo', modified=True)
+            result = MagicMock(path="/foo", modified=True)
             fabsync.isync.return_value = [result]
-            results = list(mod.isync(c, root, 'foo', tags={'bar'}))
+            results = list(mod.isync(c, root, "foo", tags={"bar"}))
             self.assertEqual(results, [result])
-            fabsync.isync.assert_called_once_with(c, root, selector=fabsync.ItemSelector.new('foo', tags={'bar'}))
+            fabsync.isync.assert_called_once_with(
+                c, root, selector=fabsync.ItemSelector.new("foo", tags={"bar"})
+            )
 
 
 class TestCheckIsync(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        root = mod.make_root('files')
-        with patch.object(mod, 'isync') as isync:
+        root = mod.make_root("files")
+        with patch.object(mod, "isync") as isync:
 
             # file(s) modified
-            result = MagicMock(path='/foo', modified=True)
+            result = MagicMock(path="/foo", modified=True)
             isync.return_value = [result]
             self.assertTrue(mod.check_isync(c, root))
 
             # not modified
-            result = MagicMock(path='/foo', modified=False)
+            result = MagicMock(path="/foo", modified=False)
             isync.return_value = [result]
             self.assertFalse(mod.check_isync(c, root))
diff --git a/tests/test_util.py b/tests/test_util.py
index 3793f93..7859634 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -11,17 +11,17 @@ class TestExists(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        mod.exists(c, '/foo')
-        c.run.assert_called_once_with('test -e /foo', warn=True)
+        mod.exists(c, "/foo")
+        c.run.assert_called_once_with("test -e /foo", warn=True)
 
 
 class TestHomePath(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        c.run.return_value.stdout = '/home/foo'
-        path = mod.get_home_path(c, user='foo')
-        self.assertEqual(path, '/home/foo')
+        c.run.return_value.stdout = "/home/foo"
+        path = mod.get_home_path(c, user="foo")
+        self.assertEqual(path, "/home/foo")
 
 
 class TestIsSymlink(TestCase):
@@ -29,13 +29,13 @@ class TestIsSymlink(TestCase):
     def test_yes(self):
         c = MagicMock()
         c.run.return_value.failed = False
-        self.assertTrue(mod.is_symlink(c, '/foo'))
+        self.assertTrue(mod.is_symlink(c, "/foo"))
         c.run.assert_called_once_with('test -L "$(echo /foo)"', warn=True)
 
     def test_no(self):
         c = MagicMock()
         c.run.return_value.failed = True
-        self.assertFalse(mod.is_symlink(c, '/foo'))
+        self.assertFalse(mod.is_symlink(c, "/foo"))
         c.run.assert_called_once_with('test -L "$(echo /foo)"', warn=True)
 
 
@@ -43,31 +43,39 @@ class TestMakoRenderer(TestCase):
 
     def test_basic(self):
         c = MagicMock()
-        renderer = mod.mako_renderer(c, env={'machine_is_live': True})
+        renderer = mod.mako_renderer(c, env={"machine_is_live": True})
         here = os.path.dirname(__file__)
-        path = os.path.join(here, 'files', 'bar', 'baz')
+        path = os.path.join(here, "files", "bar", "baz")
         rendered = renderer(path, vars={})
-        self.assertEqual(rendered, 'machine_is_live = True')
+        self.assertEqual(rendered, "machine_is_live = True")
 
 
 class TestSetTimezone(TestCase):
 
     def test_symlink(self):
         c = MagicMock()
-        with patch.object(mod, 'is_symlink') as is_symlink:
+        with patch.object(mod, "is_symlink") as is_symlink:
             is_symlink.return_value = True
-            mod.set_timezone(c, 'America/Chicago')
-            c.run.assert_has_calls([
-                call("bash -c 'echo America/Chicago > /etc/timezone'"),
-            ])
-            c.run.assert_called_with('ln -sf /usr/share/zoneinfo/America/Chicago /etc/localtime')
+            mod.set_timezone(c, "America/Chicago")
+            c.run.assert_has_calls(
+                [
+                    call("bash -c 'echo America/Chicago > /etc/timezone'"),
+                ]
+            )
+            c.run.assert_called_with(
+                "ln -sf /usr/share/zoneinfo/America/Chicago /etc/localtime"
+            )
 
     def test_not_symlink(self):
         c = MagicMock()
-        with patch.object(mod, 'is_symlink') as is_symlink:
+        with patch.object(mod, "is_symlink") as is_symlink:
             is_symlink.return_value = False
-            mod.set_timezone(c, 'America/Chicago')
-            c.run.assert_has_calls([
-                call("bash -c 'echo America/Chicago > /etc/timezone'"),
-            ])
-            c.run.assert_called_with('cp /usr/share/zoneinfo/America/Chicago /etc/localtime')
+            mod.set_timezone(c, "America/Chicago")
+            c.run.assert_has_calls(
+                [
+                    call("bash -c 'echo America/Chicago > /etc/timezone'"),
+                ]
+            )
+            c.run.assert_called_with(
+                "cp /usr/share/zoneinfo/America/Chicago /etc/localtime"
+            )
diff --git a/tests/test_wutta.py b/tests/test_wutta.py
index 1b8436c..ca08919 100644
--- a/tests/test_wutta.py
+++ b/tests/test_wutta.py
@@ -12,15 +12,29 @@ class TestPurgeEmailSettings(TestCase):
         c = MagicMock()
         sql = MagicMock()
         postgres = MagicMock(sql=sql)
-        with patch.object(mod, 'postgres', new=postgres):
-            mod.purge_email_settings(c, 'testy', appname='wuttatest')
-            sql.assert_has_calls([
-                call(c, "delete from setting where name like 'wuttatest.email.%.sender';",
-                     database='testy'),
-                call(c, "delete from setting where name like 'wuttatest.email.%.to';",
-                     database='testy'),
-                call(c, "delete from setting where name like 'wuttatest.email.%.cc';",
-                     database='testy'),
-                call(c, "delete from setting where name like 'wuttatest.email.%.bcc';",
-                     database='testy'),
-            ])
+        with patch.object(mod, "postgres", new=postgres):
+            mod.purge_email_settings(c, "testy", appname="wuttatest")
+            sql.assert_has_calls(
+                [
+                    call(
+                        c,
+                        "delete from setting where name like 'wuttatest.email.%.sender';",
+                        database="testy",
+                    ),
+                    call(
+                        c,
+                        "delete from setting where name like 'wuttatest.email.%.to';",
+                        database="testy",
+                    ),
+                    call(
+                        c,
+                        "delete from setting where name like 'wuttatest.email.%.cc';",
+                        database="testy",
+                    ),
+                    call(
+                        c,
+                        "delete from setting where name like 'wuttatest.email.%.bcc';",
+                        database="testy",
+                    ),
+                ]
+            )