Lua entry thread aborted: runtime error bad argument #2 to 'tonumber' (number expected, got string)

Question

Im using lapis framework and torch, sometimes the website showing internal server error when trying to load page, and the error from lapis is:

[error] 3726#81246: *19 lua entry thread aborted: runtime error: ...s/MyUser/torch/install/share/lua/5.1/xlua/init.lua:227: bad argument #2 to 'tonumber' (number expected, got string)
stack traceback:
coroutine 0:
    [C]: in function 'require'
    .../MyUser/torch/install/share/lua/5.1/lapis/init.lua:15: in function 'serve'
    content_by_lua(nginx.conf.compiled:22):2: in function <content_by_lua(nginx.conf.compiled:22):1>, client: 127.0.0.1, server: , request: "GET /recommend HTTP/1.1", host: "localhost:9999", referrer: "http://localhost:9999/home"

After looking arround, the problem is gone when i remark this part:

local lapis = require("lapis")
local config = require("lapis.config").get()
local inspect = require("inspect")
local json = require('cjson')
local kb_recommend = require("recommender.knowledge")
-- local cb_recommend = require("recommender.content") <---- remark this

local mysql = require "luasql.mysql"
local env = mysql.mysql()
local conn = env:connect("restoran", "root", "")

Thats link to file recommender/content.lua:

package.path = package.path .. ";../?.lua"
local predictor = require("Content Based.predictor")
return predictor

This file returning the class where i wrote my torch code. I suspect the problem is coming from the 'require' part, but dont know why? I've been looking on google for solution, and nothing found. This my current version:

Lua 5.1.5
Torch7 
Lapis 1.6.0
nginx/1.13.9
openresty/1.13.6.1

anyone can help? im very newbie in Lua environment.

Answer 1

tonumber is a Lua function for an example like this: tonumber("10") or tonumber(10)

I'm sorry I couldn't be of more help.

If you could show us the line where the error is located, I can most likely determine a fix for you.