Should it build with SUPPORT_TLS=YES and TLS_LIBS=-lssl -lcrypto commented out?
Obviously I wouldn't build it for real use without TLS, but I was surprised to see it fail due to tls_tempfail_tryclear not being available when it wasn't configured to support TLS. I guess this is probably a case of me doing something silly, but, if I can configure it to build without TLS, then I don't think I should need TLS_LIBS?