diff --git a/README.md b/README.md
index 4cab66d..0af74f4 100644
--- a/README.md
+++ b/README.md
@@ -111,10 +111,10 @@ this community's docs work" from drifting apart.
 
 ```bash
 # read side
-cd js && npm install && npm test
+(cd js && npm install && npm test)
 
 # write side
-cd python && python3 -m unittest discover -s tests -v
+(cd python && PYTHONPATH=src python3 -m unittest discover -s tests -v)
 ```
 
 CI runs both on every push and pull request.
diff --git a/js/README.md b/js/README.md
index ba9bf31..0442fed 100644
--- a/js/README.md
+++ b/js/README.md
@@ -122,7 +122,7 @@ docs.resolveLink('rules.md', 'handbook/getting-started.md');
 
 | Option | Default | What it does |
 |---|---|---|
-| `repo` | *(required)* | `owner/repo`, or a GitHub URL. Validated when the client is built — the only place this package throws. |
+| `repo` | *(required)* | `owner/repo`, or a GitHub URL. Validated when the client is built, and an unusable value throws there. (`webUrl` and `rawUrl` also throw, for a target that is not in the catalogue; `fetchMarkdown` returns `not-listed` instead.) |
 | `ref` | `'HEAD'` | The git ref to read. `HEAD` resolves to the default branch whatever it is called. |
 | `token` | none | A read token, for a private repository. Omit for a public one. |
 | `transport` | `'api'` with a token, `'raw'` without | Contents API vs `raw.githubusercontent.com`. |
diff --git a/python/README.md b/python/README.md
index 9c1b42b..e165142 100644
--- a/python/README.md
+++ b/python/README.md
@@ -134,7 +134,8 @@ a control that depends on somebody else's behaviour is not a control.
 ## Development
 
 ```bash
-python3 -m unittest discover -s tests -v
+# from python/, with src/ on the path — or after `pip install -e .`
+PYTHONPATH=src python3 -m unittest discover -s tests -v
 ```
 
 The tests mock `urllib.request.urlopen` with a small fake GitHub API keyed on