i use this primarily on os x, so we should wrap these flags in a conditional: 

```
UNAME := $(shell uname)

ifeq ($(UNAME), Linux)
	override LDFLAGS += -ltinfo -ldl
endif
```

it's a little odd that they're required for you though because i've built on several fresh ubuntu installs without them. out of curiousity, what ubuntu version and compiler / compiler version are you using?