diff --git a/.codecov.yml b/.codecov.yml
index df1eb5e01..166190c5e 100644
--- a/.codecov.yml
+++ b/.codecov.yml
@@ -40,3 +40,9 @@ codecov:
   # repositories have coverage uploaded to the right place in codecov so
   # their reports aren't incomplete.
   token: "abf679b6-e2e6-4b33-b7b5-6cfbd41ee691"
+
+  notify:
+    # The reference documentation suggests that this is the default setting:
+    # https://docs.codecov.io/docs/codecovyml-reference#codecovnotifywait_for_ci
+    # However observation suggests otherwise.
+    wait_for_ci: true
diff --git a/newsfragments/3567.minor b/newsfragments/3567.minor
new file mode 100644
index 000000000..e69de29bb
diff --git a/newsfragments/3568.minor b/newsfragments/3568.minor
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/allmydata/test/common_util.py b/src/allmydata/test/common_util.py
index 168714492..16e744902 100644
--- a/src/allmydata/test/common_util.py
+++ b/src/allmydata/test/common_util.py
@@ -57,10 +57,10 @@ def run_cli_native(verb, *args, **kwargs):
     Most code should prefer ``run_cli_unicode`` which deals with all the
     necessary encoding considerations.
 
-    :param native_str verb: The command to run.  For example, ``b"create-node"``.
+    :param native_str verb: The command to run.  For example, ``"create-node"``.
 
     :param [native_str] args: The arguments to pass to the command.  For example,
-        ``(b"--hostname=localhost",)``.
+        ``("--hostname=localhost",)``.
 
     :param [native_str] nodeargs: Extra arguments to pass to the Tahoe executable
         before ``verb``.
diff --git a/src/allmydata/test/test_storage_client.py b/src/allmydata/test/test_storage_client.py
index 18caccc5d..3a21dfd9e 100644
--- a/src/allmydata/test/test_storage_client.py
+++ b/src/allmydata/test/test_storage_client.py
@@ -457,7 +457,8 @@ class StoragePluginWebPresence(AsyncTestCase):
         self.storage_plugin = u"tahoe-lafs-dummy-v1"
 
         from twisted.internet import reactor
-        _, port_endpoint = self.port_assigner.assign(reactor)
+        _, webport_endpoint = self.port_assigner.assign(reactor)
+        tubport_location, tubport_endpoint = self.port_assigner.assign(reactor)
 
         tempdir = TempDir()
         self.useFixture(tempdir)
@@ -468,8 +469,12 @@ class StoragePluginWebPresence(AsyncTestCase):
                 "web": "1",
             },
             node_config={
-                "tub.location": "127.0.0.1:1",
-                "web.port": ensure_text(port_endpoint),
+                # We don't really need the main Tub listening but if we
+                # disable it then we also have to disable storage (because
+                # config validation policy).
+                "tub.port": tubport_endpoint,
+                "tub.location": tubport_location,
+                "web.port": ensure_text(webport_endpoint),
             },
             storage_plugin=self.storage_plugin,
             basedir=self.basedir,
diff --git a/src/allmydata/test/test_system.py b/src/allmydata/test/test_system.py
index 192b82e78..e8b27fa69 100644
--- a/src/allmydata/test/test_system.py
+++ b/src/allmydata/test/test_system.py
@@ -70,7 +70,13 @@ from ..scripts.common import (
 
 def run_cli(*args, **kwargs):
     """
-    Backwards compatible version so we don't have to change all the tests.
+    Run a Tahoe-LAFS CLI utility, but inline.
+
+    Version of run_cli_unicode() that takes any kind of string, and the
+    command-line args inline instead of as verb + list.
+
+    Backwards compatible version so we don't have to change all the tests that
+    expected this API.
     """
     nodeargs = [ensure_text(a) for a in kwargs.pop("nodeargs", [])]
     kwargs["nodeargs"] = nodeargs
@@ -658,7 +664,7 @@ def flush_but_dont_ignore(res):
 
 def _render_config(config):
     """
-    Convert a ``dict`` of ``dict`` of ``bytes`` to an ini-format string.
+    Convert a ``dict`` of ``dict`` of ``unicode`` to an ini-format string.
     """
     return u"\n\n".join(list(
         _render_config_section(k, v)
@@ -668,8 +674,8 @@ def _render_config(config):
 
 def _render_config_section(heading, values):
     """
-    Convert a ``bytes`` heading and a ``dict`` of ``bytes`` to an ini-format
-    section as ``bytes``.
+    Convert a ``unicode`` heading and a ``dict`` of ``unicode`` to an ini-format
+    section as ``unicode``.
     """
     return u"[{}]\n{}\n".format(
         heading, _render_section_values(values)
@@ -677,8 +683,8 @@ def _render_config_section(heading, values):
 
 def _render_section_values(values):
     """
-    Convert a ``dict`` of ``bytes`` to the body of an ini-format section as
-    ``bytes``.
+    Convert a ``dict`` of ``unicode`` to the body of an ini-format section as
+    ``unicode``.
     """
     return u"\n".join(list(
         u"{} = {}".format(k, v)
diff --git a/src/allmydata/util/base32.py b/src/allmydata/util/base32.py
index 75625c817..efad58841 100644
--- a/src/allmydata/util/base32.py
+++ b/src/allmydata/util/base32.py
@@ -134,8 +134,7 @@ def a2b(cs):
     @param cs the base-32 encoded data (as bytes)
     """
     # Workaround Future newbytes issues by converting to real bytes on Python 2:
-    if hasattr(cs, "__native__"):
-        cs = cs.__native__()
+    cs = backwardscompat_bytes(cs)
     precondition(could_be_base32_encoded(cs), "cs is required to be possibly base32 encoded data.", cs=cs)
     precondition(isinstance(cs, bytes), cs)
 
diff --git a/src/allmydata/web/common.py b/src/allmydata/web/common.py
index 98f915a1e..2832cc6a8 100644
--- a/src/allmydata/web/common.py
+++ b/src/allmydata/web/common.py
@@ -211,7 +211,15 @@ def compute_rate(bytes, seconds):
     return 1.0 * bytes / seconds
 
 def abbreviate_rate(data):
-    # 21.8kBps, 554.4kBps 4.37MBps
+    """
+    Convert number of bytes/second into human readable strings (unicode).
+
+    Uses metric measures, so 1000 not 1024, e.g. 21.8kBps, 554.4kBps, 4.37MBps.
+
+    :param data: Either ``None`` or integer.
+
+    :return: Unicode string.
+    """
     if data is None:
         return u""
     r = float(data)
@@ -222,7 +230,15 @@ def abbreviate_rate(data):
     return u"%.0fBps" % r
 
 def abbreviate_size(data):
-    # 21.8kB, 554.4kB 4.37MB
+    """
+    Convert number of bytes into human readable strings (unicode).
+
+    Uses metric measures, so 1000 not 1024, e.g. 21.8kB, 554.4kB, 4.37MB.
+
+    :param data: Either ``None`` or integer.
+
+    :return: Unicode string.
+    """
     if data is None:
         return u""
     r = float(data)
diff --git a/src/allmydata/web/common_py3.py b/src/allmydata/web/common_py3.py
index 9d4435706..b91f53a3a 100644
--- a/src/allmydata/web/common_py3.py
+++ b/src/allmydata/web/common_py3.py
@@ -105,6 +105,13 @@ class MultiFormatResource(resource.Resource, object):
 
 
 def abbreviate_time(data):
+    """
+    Convert number of seconds into human readable string.
+
+    :param data: Either ``None`` or integer or float, seconds.
+
+    :return: Unicode string.
+    """
     # 1.23s, 790ms, 132us
     if data is None:
         return u""