this derivation will be built:
  /nix/store/yzgigl8q1vm5afwcwl39q1azvxvmxdmp-harmonia-llvm-cov-3.3.0.drv

post-build step Upload coverage to codecov: ok
No coverage JSON found in /nix/store/vwi6wgcdr1jnd4l5l63rp57kaf8hrnym-harmonia-llvm-cov-3.3.0