Do not register system tree if installing to ~/.luarocks

See https://github.com/luarocks/luarocks/issues/952#issuecomment-449966779

2 files changed, 2 insertions, 2 deletions

diff --git a/GNUmakefile b/GNUmakefile
index 60f08dc8..4e814740 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -35,7 +35,7 @@ $(builddir)/config-$(LUA_VERSION).lua: config.unix
         @printf -- '-- LuaRocks configuration\n\n'\
         'rocks_trees = {\n'\
         '   { name = "user", root = home .. "/.luarocks" };\n'\
-        '   { name = "system", root = "'"$(rocks_tree)"'" };\n'\
+        "$$([ "$(rocks_tree)" != "$(HOME)/.luarocks" ] && printf '   { name = "system", root = "'"$(rocks_tree)"'" };\\n')"\
         '}\n'\
         "$$([ -n "$(LUA_INTERPRETER)" ] && printf 'lua_interpreter = "%s";\\n' "$(LUA_INTERPRETER)")"\
         'variables = {\n'\
diff --git a/src/luarocks/core/cfg.lua b/src/luarocks/core/cfg.lua
index 9859c6b3..75075792 100644
--- a/src/luarocks/core/cfg.lua
+++ b/src/luarocks/core/cfg.lua
@@ -710,7 +710,7 @@ function cfg.init(lua_data, project_dir, warning)
       if cfg.home_tree then
          table.insert(cfg.rocks_trees, { name = "user", root = cfg.home_tree } )
       end
-      if hardcoded.PREFIX then
+      if hardcoded.PREFIX and hardcoded.PREFIX ~= cfg.home_tree then
          table.insert(cfg.rocks_trees, { name = "system", root = hardcoded.PREFIX } )
       end
    end