anchor.diff:    propagatedBuildInputs = [
       click
       click-default-group
  -    sanic
       jinja2
       hupper
       pint
       pluggy
  +    uvicorn
  +    aiofiles
     ];
   
     checkInputs = [
  
positive.code: , fetchFromGitHub
  , click
  , click-default-group
  , sanic
  , jinja2
  , hupper
  , pint
  
negative.code:       --replace "click-default-group==1.2" "click-default-group" \
        --replace "Sanic==0.7.0" "Sanic" \
        --replace "hupper==1.0" "hupper" \
        --replace "pint~=0.8.1" "pint" \
        --replace "Jinja2==2.10.1" "Jinja2" \
        --replace "uvicorn~=0.8.4" "uvicorn"
    '';
  
    # many tests require network access
  