Undefined reference to 'pthread_once'

[Grommish]

@dragon_123456

undefined reference to pthread_once'

[solved] Build error: undefined reference to `pthread_once'

I get the following error when compiling OpenWRT 18.06.2 on Debian Stretch for an x86_64 target. Does anyone have an idea on how to solve this error? I have followed the build instructions on https://openwrt.org/docs/guide-developer/build-system/install-buildsystem. make dirclean also did not help to solve the error. /opt/openwrt/staging_dir/host/lib/libcrypto.a(libcrypto_la-eng_all.o): In function `ENGINE_load_builtin_engines': eng_all.c:(.text+0x30): undefined reference to `pthread_once' /opt…

Looks like you need to upgrade your Ubuntu.