id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	difficulty
1234	graphs: installation failure (cannot import from undefined module: sets)	Mario Domenech Goulart	Jeremy Steward	"See http://salmonella-linux-x86-64.call-cc.org/master-debugbuild/gcc/linux/x86-64/2015/12/13/salmonella-report/install/graphs.html

That's probably caused by the change in arrays which addresses http://bugs.call-cc.org/ticket/1228
"	defect	closed	major	someday	extensions	4.9.x	fixed	graphs