How do install libraries for both Lua5.2 and 5.1 using Luarocks?

Question

I am writing a small Lua project and using Luarocks to install my 3rd-party dependencies. The default Lua version on my machine is 5.2 and up to this point everything is working just fine. However, today I have stumbled across a problem that is confusing me. I want to run my program on Lua 5.1 and Luajit to see if it would also work on those versions but I am having a hard time getting Luarocks to download the appropriate versions of the dependencies. As a last resort hack, I have tried to tell Lua5.1 to use the 5.2 libraries that Luarocks installed (by setting the `LUA_PATH` environment variable to the same value as `LUA_PATH_5_2`) but unfortunately that is not enough: my project depends on LuaFileSystem, a C-based module, so I'm going to need to have separate versions of it installed for 5.1 and 5.2. What do I have to do to install both the 5.1 and 5.2 versions of my dependencies? Do I need to pass some parameters to the`luarocks install` command? Do I need to have multiple instance…

Accepted Answer

Based on your reference to `~/.luarocks/share/lua/5.2/`, you seem to be running a Unix system (Linux or Mac). You can install the latest version of LuaRocks twice, for both Lua 5.1 and Lua 5.2 like this:

```
./configure --lua-version=5.1 --versioned-rocks-dir
make build
sudo make install
```

And then again for 5.2:

```
./configure --lua-version=5.2 --versioned-rocks-dir
make build
sudo make install
```

This will get you `/usr/local/bin/luarocks-5.1` and `/usr/local/bin/luarocks-5.2`. If you installed Lua 5.1 and 5.2 in /usr/local/, and each of them will use its own `~/.luarocks/lib/luarocks/rocks-5.x/` entry for the user tree (and `/usr/local/lib/luarocks/rocks-5.x` for the system tree), and install modules to the right location at `/usr/share/lua/5.x/` and `~/.luarocks/share/lua/5.x/` (and likewise for `lib`) appropriately.

How do install libraries for both Lua5.2 and 5.1 using Luarocks?

Solution

Problem