`type location``= t```
`type t``= Ocaml_common.Location.error```
`val createf : loc:location ‑> ('a, Caml.Format.formatter, Ppxlib__.Import.unit, t) Ppxlib__.Import.format4 ‑> 'a`
`val message : t ‑> Ppxlib__.Import.string`
`val set_message : t ‑> Ppxlib__.Import.string ‑> t`
`val register_error_of_exn : (Ppxlib__.Import.exn ‑> t Ppxlib__.Import.option) ‑> Ppxlib__.Import.unit`

Register an exception handler. Exception registered this way will be properly displayed by `report_exception`.

`val of_exn : Ppxlib__.Import.exn ‑> t Ppxlib__.Import.option`
`val to_extension : t ‑> Ppxlib__.Import.extension`

Convert an error to an extension point. The compiler recognizes this and displays the error properly.