  Gyarfas conjectured in 1985 that for all $k$, $l$, every graph with no clique
of size more than $k$ and no odd hole of length more than $l$ has chromatic
number bounded by a function of $k$ and $l$. We prove three weaker statements:
(1) Every triangle-free graph with sufficiently large chromatic number has an
odd hole of length different from five; (2) For all $l$, every triangle-free
graph with sufficiently large chromatic number contains either a 5-hole or an
odd hole of length more than $l$; (3) For all $k$, $l$, every graph with no
clique of size more than $k$ and sufficiently large chromatic number contains
either a 5-hole or a hole of length more than $l$.
