The clock function has been removed from python 3.8. See
https://github.com/BRiAl/BRiAl/commit/74d861705c77c3af7e6a2e49dd57f8d26a664072
--- a/sage-brial/brial/general_boolean_polynomial.py 2017-10-13 15:35:11.000000000 -0600
+++ b/sage-brial/brial/general_boolean_polynomial.py 2019-09-11 16:24:02.129906189 -0600
@@ -5,7 +5,6 @@ import sys
import resource
from .gbcore import *
from .memusage import *
-from time import time, clock
from .PyPolyBoRi import *
from .blocks import declare_ring, Block
from math import sqrt