  We report a systematic magnetotransport study of superconducting
infinite-layer nickelate thin films Nd$_{1-x}$Sr$_x$NiO$_2$ with $0.15 \leq x
\leq 0.225$. By suppressing superconductivity with out-of-plane magnetic fields
up to 37.5 T, we find that the normal state resistivity of
Nd$_{1-x}$Sr$_x$NiO$_2$ is characterized by a crossover from a metallic
$T^2$-behavior to an insulating log(1/$T$)-behavior for all $x$ except $x =
0.225$, at which the resistivity is predominantly metallic. The
log(1/$T$)-behavior is found to be robust against magnetic fields, inconsistent
with scenarios involving localization or Kondo scattering, and points to an
anomalous insulating state possibly driven by strong correlations. In the
metallic state, we find no evidence for non-Fermi-liquid behavior arising from
proximity to a putative quantum critical point located inside the
superconducting dome.
