Failure to compile the C code crashes rebar3

[tsloughter]

I just noticed that if there is an issue in the C code that causes compilation to fail that the plugin fails when trying to do a regex:

Error: badarg
[{re,replace,
    [[....],
      "c_src/pnvalidator_nif.cpp",
      ".../c_src/pnvalidator_nif.cpp",
      [{return,list},global]],
     [{file,"re.erl"},{line,362}]},
 {pc_compilation,exec_compiler,4,
                 [{file,"..../_build/default/plugins/pc/src/pc_compilation.erl"},
                  {line,192}]},
 {pc_compilation,compile_each,5,
                 [{file,"..../_build/default/plugins/pc/src/pc_compilation.erl"},
....