diff --git a/.github/actions/install-sphinx/action.yml b/.github/actions/install-sphinx/action.yml
index 9c022bfe4..20512b4c5 100644
--- a/.github/actions/install-sphinx/action.yml
+++ b/.github/actions/install-sphinx/action.yml
@@ -10,6 +10,8 @@ runs:
       run: |
         set -x
         sudo pip install uv --break-system-packages
+        command -v uv
+        command -v uvx
         # Check that pyproject.toml and the lock file are in sync.
         # TODO Use "uv" to install Python as well.
         : 'Note that --no-managed-python below would be implied but be explicit'
diff --git a/share/tools/create_manpage_completions.py b/share/tools/create_manpage_completions.py
index 04513bda0..6400c83c0 100755
--- a/share/tools/create_manpage_completions.py
+++ b/share/tools/create_manpage_completions.py
@@ -295,6 +295,7 @@ class Deroffer:
     g_re_word = re.compile(r"[a-zA-Z_]+")  # equivalent to the word() method
     g_re_number = re.compile(r"[+-]?\d+")  # equivalent to the number() method
     g_re_esc_char = re.compile(
+        # novermin
         r"""([a-zA-Z_]) |   # Word
                                    ([+-]?\d)   |   # Number
                                    \\              # Backslash (for escape seq)
@@ -309,6 +310,7 @@ class Deroffer:
     g_re_newline_collapse = re.compile(r"\n{3,}")
 
     g_re_font = re.compile(
+        # novermin
         r"""\\f(         # Starts with backslash f
                                (\(\S{2}) |  # Open paren, then two printable chars
                                (\[\S*?\]) |  # Open bracket, zero or more printable characters, then close bracket
@@ -2090,6 +2092,7 @@ def get_paths_from_man_locations():
             with open("/etc/man.conf", "r") as file:
                 data = file.read()
                 for key in ["MANPATH", "_default"]:
+                    # novermin
                     for match in re.findall(r"^%s\s+(.*)$" % key, data, re.I | re.M):
                         parent_paths.append(match)
         except FileNotFoundError:
diff --git a/tests/checks/python-user-facing-tools-compat.fish b/tests/checks/python-user-facing-tools-compat.fish
new file mode 100644
index 000000000..db944102d
--- /dev/null
+++ b/tests/checks/python-user-facing-tools-compat.fish
@@ -0,0 +1,28 @@
+#RUN: %fish %s
+#REQUIRES: command -v uvx
+
+set -l webconfig (status dirname)/../../share/tools/web_config/webconfig.py
+set -l create_manpage (status dirname)/../../share/tools/create_manpage_completions.py
+set -l min_version 3.5
+
+# use vermin to detect minimum Python version violations
+# features enabled:
+#   - union-types: catch `str | None` syntax (3.10+)
+#   - fstring-self-doc: catch f'{var=}' syntax (3.8+)
+set -l output (uvx vermin \
+    --no-tips \
+    --violations \
+    --feature union-types \
+    --feature fstring-self-doc \
+    --target=$min_version- \
+    $webconfig \
+    $create_manpage \
+    2>&1 | string collect)
+set -l exit_code $pipestatus[1]
+
+echo $exit_code
+# CHECK: 0
+
+if test $exit_code -ne 0
+    echo $output >&2
+end