Hi, Lua developers!
Over at Nmap, we got a report of a build failure in Lua under the OpenWrt build environment, which turned out to be because it set the AR environment variable to the path to the cross-compiler's ar command. Lua's Makefile sets it to "ar rcu" so the "rcu" commands were not being passed to the ar program. Here's the link to our mailing list discussion:
http://seclists.org/nmap-dev/2018/q2/7The patch included in that thread solves the problem by moving the "rcu" commands to ar from the AR variable into the rule where AR is used. You could also set a separate variable like