  We study the single hadron inclusive production in the forward rapidity
region in proton-nucleus collisions. We find the long-standing negative cross
section at next-to-leading-order (NLO) is driven by the large negative
threshold logarithmic contributions. We established a factorization theorem for
resumming these logarithms with systematically improvable accuracy within the
color glass condensate formalism. We demonstrate how the threshold leading
logarithmic accuracy can be realized by a suitable scale choice in the NLO
results. The NLO spectrums with the threshold logarithms resummed remain
positive and impressive agreements with experimental data are observed.
