Make error message more specific. Closes #213.
Make error message more specific. Closes #213.

xpol/luavm,xpol/luavm,xpol/luavm,usstwxy/luarocks,ignacio/luarocks,coderstudy/luarocks,rrthomas/luarocks,lxbgit/luarocks,xpol/luainstaller,keplerproject/luarocks,xpol/luainstaller,tarantool/luarocks,aryajur/luarocks,ignacio/luarocks,tarantool/luarocks,tarantool/luarocks,xpol/luainstaller,lxbgit/luarocks,starius/luarocks,tst2005/luarocks,luarocks/luarocks,starius/luarocks,xiaq/luarocks,leafo/luarocks,robooo/luarocks,robooo/luarocks,keplerproject/luarocks,leafo/luarocks,coderstudy/luarocks,rrthomas/luarocks,robooo/luarocks,keplerproject/luarocks,xpol/luavm,rrthomas/luarocks,ignacio/luarocks,aryajur/luarocks,usstwxy/luarocks,xpol/luarocks,xpol/luarocks,aryajur/luarocks,robooo/luarocks,xiaq/luarocks,tst2005/luarocks,xpol/luarocks,xpol/luavm,lxbgit/luarocks,usstwxy/luarocks,ignacio/luarocks,coderstudy/luarocks,usstwxy/luarocks,tst2005/luarocks,lxbgit/luarocks,luarocks/luarocks,starius/luarocks,rrthomas/luarocks,xiaq/luarocks,xpol/luarocks,tst2005/luarocks,xiaq/luarocks,aryajur/luarocks,keplerproject/luarocks,coderstudy/luarocks,xpol/luainstaller,starius/luarocks,leafo/luarocks,luarocks/luarocks