Hello, I'm trying to build a current mesa git shapshot with LTO, and it fails with this error in src/compiler/: (gcc-6.3.1 as of today, glibc-2.25) x86_64-pc-linux-gnu-g++ -m32 -fvisibility=hidden -Werror=pointer-arith -Werror=vla -O3 -march=haswell -mtune=haswell-flto=9 -fno-fat-lto-objects -pipe -Wall -fno-math-errno -fno-trapping-math -Wl,-O1 -o glsl_compiler glsl/main.o -Wl,--as-needed glsl/.libs/libstandalone.a -lz -lpthread /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/32/libstdc++.so: undefined reference to `pthread_create' /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/32/libstdc++.so: undefined reference to `pthread_once' /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/32/libstdc++.so: undefined reference to `pthread_join' Any ideas why pthread_once() can't be found? /lib32/libpthread.so does have all the above mentioned symbols. Without LTO, it builds just fine (however performance of the library suffers, lto helps mesa a lot). Thank you! Manuel