component/python3: run test suite at compile time

component/python3/buildout.cfg

@@ -37,9 +37,10 @@ configure-options =
   --with-system-expat
   --with-system-ffi
   --with-threads
-# Profiled build:
+# Profiled build: https://github.com/python/cpython#profile-guided-optimization
   --enable-optimizations
 pre-install = mkdir profile-opt
+make-targets = test install
 
 # the entry "-Wl,-rpath=${file:location}/lib" below is needed by python-magic,
 # which would otherwise load the system libmagic.so with ctypes