Issue #26798: Hello Winndows, my old friend. I've come to fix blake2 for you again.

PC/config.c

@@ -23,6 +23,7 @@ extern PyObject* PyInit__signal(void);
 extern PyObject* PyInit__sha1(void);
 extern PyObject* PyInit__sha256(void);
 extern PyObject* PyInit__sha512(void);
+extern PyObject* PyInit__blake2(void);
 extern PyObject* PyInit_time(void);
 extern PyObject* PyInit__thread(void);
 #ifdef WIN32
@@ -96,6 +97,7 @@ struct _inittab _PyImport_Inittab[] = {
     {"_sha1", PyInit__sha1},
     {"_sha256", PyInit__sha256},
     {"_sha512", PyInit__sha512},
+    {"_blake2", PyInit__blake2},
     {"time", PyInit_time},
 #ifdef WITH_THREAD
     {"_thread", PyInit__thread},