Building with Lua 5.2 and 5.3 fails

[legends2k]

The rock fltk4lua depends on luarocks-build-cpp for building the rock. Trying

luarocks install fltk4lua FLTK_DIR=F:/Libs/FLTK

gives the error

Installing https://luarocks.org/fltk4lua-0.1-1.src.rock...
Using https://luarocks.org/fltk4lua-0.1-1.src.rock... switching to 'build' mode

Error: Failed initializing build back-end for build type 'cpp': f:\apps\lua\/share/lua/5.3/luarocks\build\cpp.lua:3: attempt to call a nil value (global 'module')

The Lua interpreter I've is version 5.3; this doesn't have the function module defined in the standard library like 5.1 did. Lua 5.2 deprecated module.

[cxw42]

To build fltk4lua on Lua 5.3 on mingw, I had to edit /mingw/share/lua/5.3/luarocks/build/cpp.lua as follows after installing the rock.

• Comment out the module(...) line at the top

• Function luarocks.build.build_rockspec calls pcall(require, "luarocks.build." .. build_spec.type), so we are going to change luarocks.build.cpp to a new-style module. That involves two changes:

  • Add just after the module line:

    local M = {}

  • Add at the very end of the file:

    return M

• Now change the definition of the exported function to be a member of M. Change:

  function run(rockspec)

  to:

  M.run = function(rockspec)

• Replace all instances of unpack with table.unpack (there were 9, when I did this)