[luarocks] fix compiler issues on CLANG64 and CLANGARM64, and update to 3.11.1

[luau-project]

Warning

It is a long PR. Two issues are reproduced, and the working fix is shown.

Description

Today, I found that the current package mingw-w64-lua-luarocks has two independent issues:

1. On CLANG64 and CLANGARM64 environments, luarocks is built with a configuration to fallback to gcc as the default C compiler, which causes Lua modules written in C fail to build / install;
2. luarocks fails to uninstall luafilesystem properly after a previous lfs package installation.

Note

Issue 2 has already been reported upstream luarocks/luarocks#1428, and fixed at luarocks/luarocks#1616. However, it still persists here without a proper fix.

Of lesser importance, MSYS2 is running version 3.9.2, while the latest luarocks release is 3.11.1.

Tip

I verified (cloned the branch and installed) that #20461 updates to 3.11.1, but the issues described here still persists with the solution provided there. So, I would like to invite @sewbacca and @Biswa96 to review this PR.

Table of Contents

• Reproduction of Issue 1
• Reproduction of Issue 2
• After the fix

Reproduction of Issue 1

1. Close any MSYS2 shell and launch a fresh CLANG64 shell

Important

• CC environment variable must not be set
• Make sure that luafilesystem is not installed for the current environment (either by luarocks, or by mingw-w64-clang-x86_64-lua-luafilesystem).

2. Install luarocks:

   pacman -S ${MINGW_PACKAGE_PREFIX}-lua-luarocks

3. Try to install any Lua package that has components written in C. For instance, luafilesystem is enough for the test:

   luarocks install luafilesystem

   The resulting output should be like this:

   

4. Leave the shell opened and untouched for the reproduction of the issue 2.

Reproduction of Issue 2

Note

We are going to continue with the shell left opened from the issue 1.

1. The issue 1 can be remedied by setting the CC environment variable, because luarocks will use it to build the C parts of a Lua module. So, set CC environment variable to the correct compiler:

   export CC=cc

2. Try again to install luafilesystem (it should succeed):

   luarocks install luafilesystem

3. List luarocks and check that luafilesystem was installed properly:

   luarocks list

4. Remove luafilesystem through luarocks:

   luarocks remove luafilesystem

5. Check that luarocks said to have removed luafilesystem properly, but did not:

   lua -e "print(require 'lfs')"

Note

lfs.dll can still be found at /clang64/lib/lua/5.4/lfs.dll

6. Go ahead and remove it manually:

   rm ${MINGW_PREFIX}/lib/lua/5.4/lfs.dll

   

After the fix

Initial setup

1. Close any MSYS2 shell and launch a fresh CLANG64 shell

Note

Ideally, CC environment variable should not be set. Remember that issue 1 can be bypassed by setting CC.

2. Uninstall luarocks in case it is already installed, and also make sure that luafilesystem is not installed for the current environment (either by luarocks, or by mingw-w64-clang-x86_64-lua-luafilesystem);
3. Download GitHub artifacts from the build and install them.

Check that issues 1 and 2 were fixed

1. Install luafilesystem:

   luarocks install luafilesystem

2. List luarocks and check that luafilesystem was installed properly:

   luarocks list

3. Remove luafilesystem through luarocks:

   luarocks remove luafilesystem

4. Check that luarocks removed luafilesystem properly, and it cannot find lfs.dll anymore

   lua -e "print(require 'lfs')"