for local development, I run "opam install mirage" (to get the
dependencies), you may pass --deps-only to opam to not compile mirage.
Then, you can use "opam pin add -k git mirage
pwd#HEAD" which tells
opam to use your current
pwd for mirage... for mirage itself this is
not needed, but if you need to modify dependencies this is the way to do
it (to have opam install local versions of libraries). See
http://opam.ocaml.org/doc/Usage.html#opampin for some documentation.
Keep in mind that opam's default mode for paths is weird, the "-k git"
option will use git HEAD for building (thus, you've to commit your local
changes locally). In the default mode, where the directory is used
directly, spurious build products from manual builds may end up in
strange errors. (NOTE: opam2 has a more sane pinning mechanism IIRC)