buildx failed with: ERROR: failed to solve: process "/dev/.buildkit_qemu_emulator /bin/sh -c addgroup --system nixbld && adduser gitpod nixbld && for i in $(seq 1 30); do useradd -ms /bin/bash nixbld$i && adduser nixbld$i nixbld; done && mkdir -m 0755 /nix && chown gitpod /nix && mkdir -p /etc/nix && echo 'sandbox = false' > /etc/nix/nix.conf && echo 'experimental-features = nix-command flakes' >> /etc/nix/nix.conf" did not complete successfully: exit code: 255