File "/nix/store/9343idj1kmww2y4g3z4z4c3wll12k1za-glasgow-unstable/lib/python3.7/site-packages/glasgow/applet/internal/lightshow/__init__.py", line 17, in counter
    d += ctr.eq(Mux(ctr == 0, ctr.reset, Mux(up, ctr + 1, ctr - 1)))
  File "/nix/store/k29x6nyc4wi1jq2833xsv36bfgclgi77-python3.7-nmigen-unstable-2019-09-28/lib/python3.7/site-packages/nmigen/hdl/ast.py", line 526, in Mux
    if len(sel) != 1:
TypeError: object of type 'bool' has no len()