opam install mirage-http

===== ERROR while installing ssl.0.4.7 =====
# opam-version 1.1.1
# os           linux
# command      ./configure --prefix /home/x/.opam/system
# path         /home/x/.opam/system/build/ssl.0.4.7
# compiler     system (4.01.0)
# exit-code    1
# env-file     /home/x/.opam/system/build/ssl.0.4.7/ssl-24887-736596.env
# stdout-file  /home/x/.opam/system/build/ssl.0.4.7/ssl-24887-736596.out
# stderr-file  /home/x/.opam/system/build/ssl.0.4.7/ssl-24887-736596.err
### stdout ###
# ...[truncated]
# checking for ocamldep... /usr/bin/ocamldep
# checking for ocamllex... /usr/bin/ocamllex
# checking for ocamlyacc... /usr/bin/ocamlyacc
# checking for ocamldoc... /usr/bin/ocamldoc
# checking for ocamlmktop... /usr/bin/ocamlmktop
# checking for gcc... (cached) gcc
# checking whether we are using the GNU C compiler... (cached) yes
# checking whether gcc accepts -g... (cached) yes
# checking for gcc option to accept ISO C89... (cached) none needed
# checking for SSL_new in -lssl... no
### stderr ###
# configure: error: Cannot find libssl.