build/luarocks: apply "Fix siteconfig" patch

upstream: https://github.com/luarocks/luarocks/pull/774

third-party/CMakeLists.txt

@@ -50,11 +50,9 @@ endif()
 
 option(USE_EXISTING_SRC_DIR "Skip download of deps sources in case of existing source directory." OFF)
 
-if(WIN32)
-  find_package(Git)
-  if(NOT Git_FOUND)
-    message(FATAL_ERROR "Git is required to apply patches for Windows.")
-  endif()
+find_package(Git)
+if(NOT Git_FOUND)
+  message(FATAL_ERROR "Git is required to apply patches to bundled dependencies")
 endif()
 
 if(UNIX)

third-party/cmake/BuildLuarocks.cmake

@@ -70,6 +70,10 @@ if(UNIX OR (MINGW AND CMAKE_CROSSCOMPILING))
   endif()
 
   BuildLuarocks(
+    PATCH_COMMAND
+      ${GIT_EXECUTABLE} -C ${DEPS_BUILD_DIR}/src/luarocks init
+      COMMAND ${GIT_EXECUTABLE} -C ${DEPS_BUILD_DIR}/src/luarocks apply
+      ${CMAKE_CURRENT_SOURCE_DIR}/patches/luarocks-Fix-siteconfig.patch
     CONFIGURE_COMMAND ${DEPS_BUILD_DIR}/src/luarocks/configure
       --prefix=${HOSTDEPS_INSTALL_DIR} --force-config ${LUAROCKS_OPTS}
     INSTALL_COMMAND ${MAKE_PRG} bootstrap)

third-party/patches/luarocks-Fix-siteconfig.patch

@@ -0,0 +1,28 @@
+From dad6687372b1568f1543388d5014190a076e388a Mon Sep 17 00:00:00 2001
+Date: Thu, 8 Mar 2018 22:50:52 +0100
+Subject: [PATCH] Fix site_config
+
+---
+ src/luarocks/cfg.lua | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/luarocks/cfg.lua b/src/luarocks/cfg.lua
+index 1d5c9872e205..aa34a4f9748b 100644
+--- a/src/luarocks/cfg.lua
++++ b/src/luarocks/cfg.lua
+@@ -23,10 +23,10 @@ local version_suffix = cfg.lua_version:gsub("%.", "_")
+ 
+ -- Load site-local global configurations
+ local ok, site_config = pcall(require, "luarocks.site_config_"..version_suffix)
+-if not ok then
++if not ok or type(site_config) ~= "table" then
+    ok, site_config = pcall(require, "luarocks.site_config")
+ end
+-if not ok then
++if not ok or type(site_config) ~= "table" then
+    io.stderr:write("Site-local luarocks/site_config.lua file not found. Incomplete installation?\n")
+    site_config = {}
+ end
+-- 
+2.7.4
+