this derivation will be built:
  /nix/store/m5a6aslfzrfpchpxj8jcl1m18q4fpl7q-omp-18.2.4.drv
building '/nix/store/m5a6aslfzrfpchpxj8jcl1m18q4fpl7q-omp-18.2.4.drv'
omp-18.2.4> Running phase: unpackPhase
omp-18.2.4> unpacking source archive /nix/store/w3lhcv5x48gqgrdnh9dvfmm78l0cmb89-source
omp-18.2.4> source root is source