@bucky This isn’t a Glow-specific issue, this is related to building folly which is a dependency of Glow. So I am not totally sure what the issue might be, or if it’s the version of OpenSSL you’re using. How did you install that version? It looks like on the folly page for 16.04 they just installed libssl-dev through apt-get, perhaps you could find out what version that is and use it too…