this derivation will be built:
  /nix/store/8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv
building '/nix/store/8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv' on 'grpc://farm.numtide.com:50051?client-cert=/run/secrets/vars/per-machine/bld1/nix-farm-ci/crt&client-key=/run/secrets/vars/per-machine/bld1/nix-farm-ci/key&connect-timeout=22&system=aarch64-linux'
8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv: elastic-arm-30402bd3: not scheduled here: 8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv, asking the scheduler again
8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv: elastic-arm-d29ff195: not scheduled here: 8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv, asking the scheduler again
building '/nix/store/8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv' on farm.numtide.com:50051
spec-jsonfmt> elastic-arm-d29ff195: building 8a5bj2ynssh5az956xvs8x94ldq485i4-spec-jsonfmt.drv
spec-jsonfmt> Error: failed to format json file: invalid/a.json: invalid character ',' looking for beginning of object key string
spec-jsonfmt> Error: failed to format json file: invalid/a.json: invalid character ',' looking for beginning of object key string

upload niks3: ok