Currently, 8.1 trunk doesn't build with CONFIGUREARGS=--enable-werror on GCC 5.3.1, due to a couple of small issues. I've pushed fixes to the rosuav/enable-werror branch; can someone please try this on a different system, different compiler, etc, to see if it breaks anything?
The three changes are: 1) Add a #include to ensure that a function is available. 2) Enable a block of code that was otherwise restricted to PIKE_DEBUG mode 3) Work around a spurious GCC warning!
ChrisA