src/sage/misc/cython.py: Add doctests for PEP 420 support, cython/cyt…

…hon#5335
mkoeppe · Mar 25, 2023 · 5ee730d · 5ee730d
1 parent f13d6e9
commit 5ee730d
Showing 1 changed file with 22 additions and 0 deletions.
diff --git a/src/sage/misc/cython.py b/src/sage/misc/cython.py
@@ -211,6 +211,28 @@ def cython(filename, verbose=0, compile_message=False,
         sage: cython('''
         ....: cdef size_t foo = 3/2
         ....: ''')
+
+    Check that Cython supports PEP 420 packages::
+
+        sage: cython('''
+        ....: cimport sage.misc.cachefunc
+        ....: ''')
+
+        sage: cython('''
+        ....: from sage.misc.cachefunc cimport cache_key
+        ....: ''')
+
+    In Cython 0.29.33 using `from PACKAGE cimport MODULE` is broken
+    when `PACKAGE` is a namespace package, see :trac:`35322`::
+
+        sage: cython('''
+        ....: from sage.misc cimport cachefunc
+        ....: ''')
+        Traceback (most recent call last):
+        ...
+        RuntimeError: Error compiling Cython file:
+        ...
+        ...: 'sage/misc.pxd' not found
     """
     if not filename.endswith('pyx'):
         print("Warning: file (={}) should have extension .pyx".format(filename), file=sys.stderr)