Before compiling, use ./scripts/instrument_dune_bisect.sh to add the bisect_ppx
preprocessing directive to the dune files of the packages to be analyzed.

Examples:
  ./scripts/instrument_dune_bisect.sh src/lib_p2p/dune
  ./scripts/instrument_dune_bisect.sh src/proto_alpha/lib_protocol/dune.inc
  ./scripts/instrument_dune_bisect.sh src/proto_alpha/ vendors/
  ./scripts/instrument_dune_bisect.sh . --except src/lib_crypto

NOTE: this file is kept present here to make sure the directory
      _coverage_output exists.  This is where coverage data will be collected
      when tests are run.  To clean it use: make coverage-clean