  We study the evolution of the coupling in SU(2) gauge field theory with
$N_f=8$ fundamental fermion flavors on the lattice. This model is expected to
have an infrared fixed point at high coupling. We use HEX-smeared Wilson-clover
action, and measure the gradient flow running coupling with Dirichlet boundary
conditions. Extrapolating our results to continuum, we find an infrared fixed
point at $g^2=8.24(59)^{+0.97}_{-1.64}$, with statistical and systematic error
estimates. We also measure the anomalous dimension of the quark mass operator,
and find its value at the fixed point $\gamma \approx 0.15 \pm 0.02$.
