Another try

requirements.txt

@@ -1,5 +1,8 @@
 # The documentation uses 'mkdocs', which is written in Python
 
+# See https://github.com/squidfunk/mkdocs-material/issues/2030
+jinja2>=2.11.1,<3.1
+
 # mkdocs
 mkdocs
 mkdocs-material