$ pwd
/home/tony/scratch/opam/test-opam-root
$ opam repository add --root $PWD satysfi-external https://github.com/gfngfn/satysfi-external-repo.git
$ opam repository add --root $PWD opam-windows-repository https://github.com/vouillon/opam-windows-repository.git
$ opam repository add --root $PWD ocamlbench-repo https://github.com/OCamlPro/ocamlbench-repo.git
$ opam repo --all --root $PWD
# Repository # Url # Switches(rank)
ocamlbench-repo git+https://github.com/OCamlPro/ocamlbench-repo.git
opam-windows-repository git+https://github.com/vouillon/opam-windows-repository.git
opam.ocaml.org https://opam.ocaml.org <default>(1)
satysfi-external git+https://github.com/gfngfn/satysfi-external-repo.git