How to install modules to Luajit using Luarocks

Question

I managed to install luasocket and works fine using lua5.3 but i can't find the way to install them to require from luajit.

If i write print(_VERSION) it shows luajit use lua5.1.

This is the stuff i been trying:

luarocks install luasocket

luarocks --local install luasocket

luarocks --lua-version 5.1 install luasocket

luarocks --lua-version 5.1 --local install luasocket

luarocks config lua_version 5.1

luarocks install luasocket

sock = require("/data/data/com.termux/files/home/.luarocks/lib/luarocks/rocks-5.1/socket")

package.path = package.path .. ";/data/data/com.termux/files/home/.luarocks/lib/luarocks/rocks-5.1" require "socket"

package.path = package.path .. ";/data/data/com.termux/files/home/.luarocks/lib/lua/5.1" require "socket"

...

The error:

$ luajit
LuaJIT 2.1.0-beta3 -- Copyright (C) 2005-2017 Mike Pall. http://luajit.org/
JIT: ON ARMv7 VFPv3 fold cse dce fwd dse narrow loop abc sink fuse
> sock = require("socket")
stdin:1: module 'socket' not found:
        no field package.preload['socket']
        no file './socket.lua'
        no file '/data/data/com.termux/files/usr/share/luajit-2.1.0-beta3/socket.lua'
        no file '/usr/local/share/lua/5.1/socket.lua'
        no file '/usr/local/share/lua/5.1/socket/init.lua'
        no file '/data/data/com.termux/files/usr/share/lua/5.1/socket.lua'
        no file '/data/data/com.termux/files/usr/share/lua/5.1/socket/init.lua'
        no file './socket.so'
        no file '/usr/local/lib/lua/5.1/socket.so'
        no file '/data/data/com.termux/files/usr/lib/lua/5.1/socket.so'
        no file '/usr/local/lib/lua/5.1/loadall.so'
stack traceback:
        [C]: in function 'require'
        stdin:1: in main chunk
        [C]: at 0xaba4406d

I tryied to move the installed files to some of those paths but still don't work.

Answer 1

Here's the thing, you stated:

"I add the path and get: /data/data/com.termux/files/home/.luarocks/share/lua/5.1/socket.lua module 'socket.core' not found..."

That's because socket.lua exists in that directory, but you moved it's subdirectory:

/data/data/com.termux/files/home/.luarocks/share/lua/5.1/socket/core.lua

So that dir will no longer do anything for you until you delete it and begin again.

rm /data/data/com.termux/files/home/.luarocks/share/lua/5.1/socket.lua
rm -rf /data/data/com.termux/files/home/.luarocks/share/lua/5.1/socket/

luarocks --lua-version 5.1 install luasocket

Now watch carefully as it installs, to see what directory it actually installs to, or use that find command I mentioned earlier to locate your Lua5.1 compatable socket location and add that to your LUA_PATH.

sudo apt install mlocate  &&  sudo updatedb  &&  locate socket.lua

You don't need to add these directories to your LUA_PATH as they're already being searched

> sock = require("socket")
stdin:1: module 'socket' not found:
        no field package.preload['socket']
        no file './socket.lua'
        no file '/data/data/com.termux/files/usr/share/luajit-2.1.0-beta3/socket.lua'
        no file '/usr/local/share/lua/5.1/socket.lua'
        no file '/usr/local/share/lua/5.1/socket/init.lua'
        no file '/data/data/com.termux/files/usr/share/lua/5.1/socket.lua'
        no file '/data/data/com.termux/files/usr/share/lua/5.1/socket/init.lua'
        no file './socket.so'
        no file '/usr/local/lib/lua/5.1/socket.so'
        no file '/data/data/com.termux/files/usr/lib/lua/5.1/socket.so'
        no file '/usr/local/lib/lua/5.1/loadall.so'

;; won't do anything because you've already pointed out that it doesn't reside in any of those default dirs.

It is possible that it's looking for the right dir, but the wrong extension.

/usr/local/lib/lua/5.1/socket.so
as opposed to /usr/local/lib/lua/5.1/socket.lua

in this case, use the softlink method I mentioned earlier, making sure to use the correct location, this is just an example:

ln -s /usr/local/lib/lua/5.1/socket.lua /usr/local/lib/lua/5.1/socket.so

Answer 2

luarocks --lua-version 5.1 install luasocket

is the proper way to install it.

That should also tell you in the last line of output where it installed the module, so you can check if that's in your package.path.

---

It seems you just misunderstand how package.path works. From the manual:

A path is a string containing a sequence of templates separated by semicolons. For each template, the function replaces each interrogation mark (if any) in the template with a copy of name wherein all occurrences of sep (a dot, by default) were replaced by rep (the system's directory separator, by default), and then tries to open the resulting file name.

What that means is that a path like /usr/share/lua/5.1 won't find anything, because it doesn't find a valid Lua file at that path and since there's no ?, no substitution is done whatsoever. The first of the two paths is OK, but many Lua modules use a file called init.lua instead, so for every <path>/?.lua you should always also add a <path>/?/init.lua to cover that option as well.

Normally Luarocks should install the packages main Lua file at /usr/local/share/lua/5.1/socket.lua, but for your case that doesn't seem to work. You can have a look at that directory and see if the file is there at all, and check that luarocks config deploy_lua_dir actually returns /usr/local/share/lua/5.1.

Answer 3

socket.lua was installed to a directory that doesn't exist in your LUA_PATH

find where socket.lua was installed, with find or mlocate, if installed:

find / -name socket.lua 2>&1 | grep -v Perm

sudo updatedb  &&  locate socket.lua

~/.luaver/luarocks/3.2.0_5.1/share/lua/5.1/socket.lua
~/.luaver/luarocks/3.2.0_5.3/share/lua/5.3/socket.lua
/usr/share/lua/5.1/socket.lua
/usr/share/lua/5.2/socket.lua
/usr/share/lua/5.3/socket.lua

edit your .bashrc -- assuming a bash shell here, but others follow a similar process. take your pick, and modify accordingly https://wiki.termux.com/wiki/Shells

find the line that says export LUA_PATH='/usr/local/share/lua/5.1/?.lua;yadda-yadda

add a semicolon plus the path(s) you found from above.

export LUA_PATH='/usr/local/share/lua/5.1/?.lua;/usr/share/lua/5.1'

close any open terminals, then open a fresh one, now that you have that new path enabled.

---

alternatively, you can use softlinks.

ln -s /usr/share/lua/5.1/socket.lua /usr/local/share/lua/5.1/socket.lua

I'm not a fan of this secondary softlink method, because you'd have to do it for every Lua module that resides outside of your path, but I'm including it so you know your options. If it's just for that particular module, this would be an acceptable solution, because it does what you set out to do. However, in the future when you run into the same issue with other modules, you would have to repeat the process for those, as well. Modifying the LUA_PATH is your best bet.