is is documented why runCommand won't export variables with CAPS in it ? If I do `inherit Onecapitalcharacter` in the env, then @Onecapitalcharacter@ never gets substitued. Everything works fine in lower case: 
`` runCommand "lua-setup-hook.sh" {
  # hum doesn't seem to like caps
  # inherit LuaPathSearchPaths;
  luapathsearchpaths=LuaPathSearchPaths;
  luacpathsearchpaths=LuaCPathSearchPaths;
} ''
``