channels: test more error conditions, test exception types
channels: test more error conditions, test exception types

cygx/roast,niner/roast,dankogai/roast,zostay/roast,dogbert17/roast,skids/roast,laben/roast,dankogai/roast,niner/roast,b2gills/roast,bitrauser/roast,dankogai/roast,laben/roast,skids/roast,dogbert17/roast,cygx/roast,perl6/roast,cygx/roast,niner/roast,zostay/roast,laben/roast,skids/roast,b2gills/roast,bitrauser/roast,b2gills/roast,zostay/roast