diff --git a/.gitignore b/.gitignore
index 301e238bb..04e7649f1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,7 @@ build/
 __pycache__
 .DS_Store
 /locales/
+
+# pixi environments
+.pixi/*
+!.pixi/config.toml
diff --git a/source/conf.py b/source/conf.py
index 68ec32a28..e2ed462c8 100644
--- a/source/conf.py
+++ b/source/conf.py
@@ -248,6 +248,12 @@
     "virtualenv": ("https://virtualenv.pypa.io/en/stable/", None),
 }
 
+# Local builds can skip external inventories when network access is restricted.
+# Sphinx injects `tags` when loading this configuration.
+if tags.has("skip-intersphinx"):  # noqa: F821
+    intersphinx_mapping = {}
+    suppress_warnings = ["ref.*"]
+
 # -- Options for todo extension --------------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/extensions/todo.html#configuration