我尝试使用最新版本的OCaml，OPAM和相关软件包在Ubuntu 14.04下编译和构建这个简单的Unikernel项目https://github.com/MagnusS/mirage-stats-demo，但是当我执行命令 make depend 出现以下错误：
make -C manifest
make[1]: Entering directory /home/osboxes/dev/mirage-stats-demo/manifest'
ocamlbuild manifest.native -pkgs unix,bytes,mirage
+ /usr/bin/ocamlc.opt -c -I /home/osboxes/.opam/system/lib/bytes -I
/home/osboxes/.opam/system/lib/cmdliner -I/home/osboxes/.opam/system/lib/fmt -I /home/osboxes/.opam/system/lib/functoria -I /home/osboxes/.opam/system/lib/ipaddr -I /home/osboxes/.opam/system/lib/mirage -I /home/osboxes/.opam/system/lib/ocamlgraph -I /home/osboxes/.opam/system/lib/result -I /home/osboxes/.opam/system/lib/rresult -I /home/osboxes/.opam/system/lib/sexplib -I /usr/lib/ocaml -o manifest.cmo manifest.ml
File "manifest.ml", line 187, characters 12-23:
Error: Unbound value Mirage.load
Command exited with code 2.
Hint: Recursive traversal of subdirectories was not enabled for this build,
as the working directory does not look like an ocamlbuild project (no
'_tags' or 'myocamlbuild.ml' file). If you have modules in subdirectories,
you should add the option "-r" or create an empty '_tags' file.
To enable recursive traversal for some subdirectories only, you can use the
following '_tags' file:
true: -traverse
<dir1> or <dir2>: traverse
Compilation unsuccessful after building 2 targets (0 cached) in 00:00:01.
make[1]: *** [all] Error 10
make[1]: Leaving directory `/home/osboxes/dev/mirage-stats-demo/manifest'
make: *** [manifest/manifest.native] Error 2