Chrome developer console debug

HALP! A bit hard of understanding this morning… I used to be able to put a breakpoint in the basic js of my site but now I only get the Blaze version?

… HTML.SPAN(“Rejected”), "\n "), "\n\n ", HTML.INPUT({…

I have my project as a source map but it doesn’t break on the line when I set the breakpoint there… I am not sure what has changed but I can’t debug…! I am having a moment. Duurh.

(I do not use react btw)

UPDATE: Okay mapped it again and it breaks okay now but I am aware that the problem as usual is between the seat and the keyboard in terms of a general and intolerable IGNORANCE about source maps - using chromium developer console. So does anyone know of a handy meteor-specific brain-injection faq/tutorial/cheatsheet on this area of development for chromium and/or iceweasel?