Use a pinned version of Cython for now, as most of the recipes are incompatible with Cython==3.x.x (#2862)

Author: misl6

Makefile

@@ -22,7 +22,7 @@ all: virtualenv
 
 $(VIRTUAL_ENV):
 	python3 -m venv $(VIRTUAL_ENV)
-	$(PIP) install Cython
+	$(PIP) install Cython==0.29.36
 	$(PIP) install -e .
 
 virtualenv: $(VIRTUAL_ENV)