A broken nipple on that tank will definitely throw an evap code, mine did .  .but it wasn't the bottom nipple that had a crack, it was the top one .  I didn't attempt to repair it ,although there are dyi s that show you how , but I doubted their reliability .  I just ended up buying a new tank . 

That's the fuel evaporative liquid/vapor separator -it's not uncommon for one of the nipples to break and cause a leak code. 

Luckily, this part is the same on all obd-2 e36s, so it's not hard to find.  Jb weld, epoxy, or even plastic welding (polypropylene iirc) could all work depending on where the crack is.  IE, if the crack is at the junction of the tank and nipple, you'd be better off replacing the whole tank. 

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