Symbol not found error using embedded Lua interpreter in Rust

[Deepak Jois <deepak.jois@...>]

I am trying to use [rust-lua53](https://github.com/jcmoyer/rust-lua53)
to execute Lua code. _rust-lua53_ already bundles the source code for
Lua 5.3.3, and provides some bindings on top of it.

It seems to run fine with regular Lua code, but when I try to load a
Lua C module, it gives a "Symbol not found" error.

The Lua code I am trying to execute is:

```
   print('hello')

    if not pcall(function() require('serpent') end) then
      print('error loading serpent')
    else
        spt = require('serpent')
        print('serpent successfully loaded')
    end

    local status, err = pcall(function() require('lfs') end)
    print(err)
```

which ends up giving the following output (on OS X, but I get
something similar on Linux):

```

hello
serpent successfully loaded
error loading module 'lfs' from file
'/Users/deepak/Downloads/lua53/lib/lua/5.3/lfs.so':
        dlopen(/Users/deepak/Downloads/lua53/lib/lua/5.3/lfs.so, 6):
Symbol not found: _lua_settable
  Referenced from: /Users/deepak/Downloads/lua53/lib/lua/5.3/lfs.so
  Expected in: flat namespace
 in /Users/deepak/Downloads/lua53/lib/lua/5.3/lfs.so
```

Could somebody help me understand where I can start troubleshooting
this? What does the Lua interpreter look for when trying to load a Lua
C module? Is there a specific way to link the Lua code inside of Rust
so that the symbols are available to the C module?

The full error report is here: https://github.com/jcmoyer/rust-lua53/issues/85

Thanks
Deepak