What is an example of a non-contractible space $X$ with $\pi_n(X) = 0$ for all $n\geq 0$ (note in particular $X$ is path connected)?
Motivation: Whitehead's theorem implies that no such CW complex $X$ exists. I'd like to know a counterexample to the "general Whitehead theorem".
A nice example is the (open) long line. Every compact subset of it is contained in a bounded interval which is homeomorphic to $[0,1]$, and thus the homotopy groups are trivial (and the space is additionally locally contractible, even locally Euclidean!). However, it is not contractible, essentially because it's "too long" to contract the whole thing with a single interval.