Hi

I’d like to build prof_spacetime but after creating a new opam switch based off of 4.07.1 I get the following error:

```
opam install prof_spacetime
The following dependencies couldn't be met:
- prof_spacetime → cohttp < 1.0 → uri < 1.5.0 → ocaml < 4.06.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → uri < 1.5.0 → sexplib < 113.01.00 → ocaml < 4.03.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → sexplib < 113.01.00 → ocaml < 4.03.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → pa_fields_conv → ocaml < 4.03
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → ocaml < 4.06.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → lwt < 2.5.0 → ocaml < 4.05.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → cstruct < 0.6.0 → ocaml < 4.06.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → conduit < 0.16.0 → pa_sexp_conv < v0.9.0 → ocaml < 4.03
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → conduit < 0.16.0 → ppx_driver < v0.10.0 → ppx_core < v0.10 → base <
v0.10 → ocaml < 4.07.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → conduit < 0.16.0 → ppx_driver < v0.10.0 → ppx_core < v0.10 → ocaml
< 4.06.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → conduit < 0.16.0 → ppx_driver < v0.10.0 → ocaml < 4.06.0
base of this switch (use `--unlock-base' to force)
- prof_spacetime → cohttp < 1.0 → conduit < 0.16.0 → sexplib < 113.24.00 → ocaml < 4.03.0
base of this switch (use `--unlock-base' to force)
```

I assume this is still the correct tool to use for profiling?

Any help would be appreciated