lpeg and lua command line

["Wesley Smith" <wesley.hoke@...>]

I'm currently working on a build tool that is essentially a variation
of lua.c.  One of its functions is to parse special tokens in source
files like C comments etc. and I wanted to try using LPEG for this
purpose.  I naively added lpeg.c to my project and added
luaopen_lpeg(L); in the appropriate place in main() of lua.c but get
the following error:

PANIC: unprotected error in call to Lua API (no calling environment)


Here's my main:

int main (int argc, char **argv) {
  int status;
  struct Smain s;

  lua_State *L = lua_open();  /* create state */
  luaopen_lfs(L);
  luaopen_lpeg(L);

  if (L == NULL) {
    l_message(argv[0], "cannot create state: not enough memory");
    return EXIT_FAILURE;
  }
  s.argc = argc;
  s.argv = argv;
  status = lua_cpcall(L, &pmain, &s);
  report(L, status);
  lua_close(L);
  return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;
}



I looked at the luaopen_lpeg function and it apparently messes with
the environment.  I'm wondering what exactly it's doing and is there a
way to not get a PANIC from including it like this?  When I comment
lpeg out, scripts run fine.

thanks for any advice,
wes