How to build a Xen unikernel of Mirage OS

Question

I read this document(http://openmirage.org/wiki/hello-world) and tried to build a xen unikernel as follows:

mirage configure --xen
make depend
make    

But failed at compilation:

ocamlbuild -classic-display -use-ocamlfind -pkgs lwt.syntax,mirage-console.xen,mirage-types.lwt -tags "syntax(camlp4o),annot,bin_annot,strict_sequence,principal" -tag-line "<static*.*>: -syntax(camlp4o)" -cflag -g -lflags -g,-linkpkg,-dontlink,unix main.native.o
ocamlfind ocamldep -package mirage-types.lwt -package mirage-console.xen -package lwt.syntax -syntax camlp4o -modules main.ml > main.ml.depends
ocamlfind ocamlc -c -g -annot -bin-annot -principal -strict-sequence -package mirage-types.lwt -package mirage-console.xen -package lwt.syntax -syntax camlp4o -o main.cmo main.ml
ocamlfind ocamlopt -c -g -annot -bin-annot -principal -strict-sequence -package mirage-types.lwt -package mirage-console.xen -package lwt.syntax -syntax camlp4o -o main.cmx main.ml
pkg-config --print-errors --exists mirage-xen
Package mirage-xen was not found in the pkg-config search path.
Perhaps you should add the directory containing `mirage-xen.pc'

to the PKG_CONFIG_PATH environment variable No package 'mirage-xen' found make: *** [build] Error 1

I installed mirage-xen by opam install mirage-xen successfully. But in my .opam directory, there are no mirage-xen.pc.

Answer 1

Chances are that your version of mirage-xen is out of date. You can update it via OPAM by:

opam update -u
opam info mirage-xen

Make sure that you have mirage-xen version 2.1.1 or greater (the latest as of this comment is 2.1.3).

If you don't pick up the upgrade, then you may have a local Git checkout of the central package database. Confirm this by looking at the output of:

opam remote

The output of this should tell you where your local git checkout is, and so navigate there and refresh from git://github.com/ocaml/opam-repository and then run opam update -u.

Answer 2

They should appear in your OPAM prefix. I get:

$ ls $(opam config var prefix)/lib/pkgconfig
gmp.pc                mirage-xen-ocaml-bindings.pc  mirage-xen-posix.pc
libminios-xen.pc      mirage-xen-ocaml.pc           openlibm.pc
mirage-xen-minios.pc  mirage-xen.pc

(you may have fewer; mirage-xen.pc is the important one)

Assuming they're there, check the project's Makefile is setting PKG_CONFIG_PATH correctly.