Compiled on Lubuntu 18.04 64-bit
GLIBC 2.27
GCC 7.5.0

 
 openSSL
./config --prefix=/usr/local/openssl-64bit --openssldir=/usr/local/openssl-64bit
make
make install



OPENSSL_PREFIX "lib" and "include" should be under "/usr/local/openssl-64bit"
/usr/local/openssl-64bit/include
/usr/local/openssl-64bit/lib

../qt-everywhere-src-5.15.13/configure -release -prefix "/opt/Qt/5.15.13/gcc_64" -opensource -confirm-license -silent -qt-zlib -qt-pcre -qt-libpng -qt-libjpeg -system-freetype -opengl desktop -make libs -make tools -flite OPENSSL_PREFIX="/usr/local/openssl-64bit" -openssl-linked