`type t`````
`include sig ... end`
`val sexp_of_t : t ‑> Parsexp__.Import.Ppx_sexp_conv_lib.Sexp.t`
`val user_exn : t ‑> exn`

Exception raised by the user function

`val sub_sexp : t ‑> Parsexp__.Import.Ppx_sexp_conv_lib.Sexp.t`

S-expression that failed to be converted

`val location : t ‑> Positions.range option`

Position of `sub_sexp t` in the original source, if found

`val report : Format.formatter ‑> filename:string ‑> t ‑> unit`

Similar to `Parse_error.report`