local luarocks package install (luarepl) does not work - lua

Question

I'm new to luarocks and I just tried to install luarepl.
The installation apparently went fine:
$ luarocks install luarepl
Installing https://luarocks.org/luarepl-0.8-1.rockspec...
Using https://luarocks.org/luarepl-0.8-1.rockspec... switching to 'build' mode
Updating manifest for /Users/me/.luarocks/lib/luarocks/rocks-5.1
luarepl 0.8-1 is now built and installed in /Users/me/.luarocks (license: MIT/X11)
but if I try to launch the executable, it seems that the installation is broken:
$ ~/.luarocks/bin/rep.lua
/usr/local/bin/lua5.1: ...cks/lib/luarocks/rocks-5.1/luarepl/0.8-1/bin/rep.lua:23: module 'repl.console' not found:
no field package.preload['repl.console']
no file './repl/console.lua'
no file '/usr/local/share/lua/5.1/repl/console.lua'
no file '/usr/local/share/lua/5.1/repl/console/init.lua'
no file '/usr/local/lib/lua/5.1/repl/console.lua'
no file '/usr/local/lib/lua/5.1/repl/console/init.lua'
no file './repl/console.so'
no file '/usr/local/lib/lua/5.1/repl/console.so'
no file '/usr/local/lib/lua/5.1/loadall.so'
no file './repl.so'
no file '/usr/local/lib/lua/5.1/repl.so'
no file '/usr/local/lib/lua/5.1/loadall.so'
stack traceback:
[C]: in function 'require'
...cks/lib/luarocks/rocks-5.1/luarepl/0.8-1/bin/rep.lua:23: in main chunk
[C]: ?
I look into the ~/.luarocks dir:
$ cd ~ ; find .luarocks
.luarocks
.luarocks/bin
.luarocks/bin/rep.lua
.luarocks/config.lua
.luarocks/lib
.luarocks/lib/luarocks
.luarocks/lib/luarocks/rocks-5.1
.luarocks/lib/luarocks/rocks-5.1/luarepl
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/bin
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/bin/rep.lua
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/doc
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/doc/COPYING
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/doc/IDEAS.md
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/doc/plugins.md
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/doc/README.md
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/doc/Roadmap.md
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/luarepl-0.8-1.rockspec
.luarocks/lib/luarocks/rocks-5.1/luarepl/0.8-1/rock_manifest
.luarocks/lib/luarocks/rocks-5.1/manifest
.luarocks/share
.luarocks/share/lua
.luarocks/share/lua/5.1
.luarocks/share/lua/5.1/repl
.luarocks/share/lua/5.1/repl/console.lua
.luarocks/share/lua/5.1/repl/init.lua
.luarocks/share/lua/5.1/repl/plugins
.luarocks/share/lua/5.1/repl/plugins/autoreturn.lua
.luarocks/share/lua/5.1/repl/plugins/completion.lua
.luarocks/share/lua/5.1/repl/plugins/example.lua
.luarocks/share/lua/5.1/repl/plugins/filename_completion.lua
.luarocks/share/lua/5.1/repl/plugins/history.lua
.luarocks/share/lua/5.1/repl/plugins/keep_last_eval.lua
.luarocks/share/lua/5.1/repl/plugins/linenoise.lua
.luarocks/share/lua/5.1/repl/plugins/pretty_print.lua
.luarocks/share/lua/5.1/repl/plugins/rcfile.lua
.luarocks/share/lua/5.1/repl/plugins/rlwrap.lua
.luarocks/share/lua/5.1/repl/plugins/semicolon_suppress_output.lua
.luarocks/share/lua/5.1/repl/sync.lua
.luarocks/share/lua/5.1/repl/utils.lua
and I can find that stuff.
I tried adding a line to config.lua to load packages from local installation to no avail:
$ cat ~/.luarocks/config.lua
local_by_default=true
(removing it has no effect)
did I miss some obvious step?
running luarocks with no arguments gives me:
CONFIGURATION
Lua version: 5.1
Configuration files:
System: /usr/local/etc/luarocks51/config-5.1.lua (ok)
User : /Users/me/.luarocks/config.lua (ok)
Rocks trees in use:
/Users/me/.luarocks ("user")
/usr/local ("system")
it seems that the user rock tree is not in the package path:
$ lua
Lua 5.1.5 Copyright (C) 1994-2012 Lua.org, PUC-Rio
> print(package.path)
./?.lua;/usr/local/share/lua/5.1/?.lua;/usr/local/share/lua/5.1/?/init.lua;/usr/local/lib/lua/5.1/?.lua;/usr/local/lib/lua/5.1/?/init.lua
why?

Answer 1

From https://github.com/luarocks/luarocks/wiki/Using-LuaRocks:
Most LuaRocks installations will feature two rocks trees:
"system" rock tree (used by default)
"user" rock tree
To be able to use the module, we need to make sure that Lua can find that dkjson.lua file when we run require("dkjson"). You can check your Lua paths from the Lua environment, using
print(package.path)
print(package.cpath)
These variables can be pre-configured from outside Lua, using the LUA_PATH and LUA_CPATH environment variables.
If you installed both Lua and LuaRocks in their default directories (/usr/local on Linux and Mac OSX), then the "system" tree is /usr/local and it will work by default. However, the "user" tree (for installing rocks without admin privileges) is not detected by Lua by default. For that we'll need to configure these environment variables.
LuaRocks offers a semi-automated way to do this. If you type the following command:
luarocks path --bin
it will print commands suitable for your platform for setting up your environment. On typical Unix terminal environments, you can type this:
eval $(luarocks path --bin)
and it apply the changes, temporarily, to your shell. To have these variables set permanently, you have to configure the environment variables to your shell configuration (for example, by adding the above line to your .bashrc file if your shell is Bash).