Exception when double-examinating a type

[MisterDA]

Using The Merlin toolkit version 38c13ee8, for Ocaml 4.13.0 (4.3.2~4.13preview), I had a crash under emacs inspecting twice the type of the r parameter in https://github.com/MisterDA/opam-health-check/blob/repro-crash-merlin/server/backend/check.ml#L32.

(unit, Capnp_rpc.Exception.t) Result.result
let: unknown answer: "exception":"Not_found
Raised at Persistent_env.find_pers_struct in file \"src/ocaml/typing/persistent_env.ml\", line 250, characters 15-30
Called from Persistent_env.find in file \"src/ocaml/typing/persistent_env.ml\" (inlined), line 303, characters 6-45
Called from Env.find_pers_mod in file \"src/ocaml/typing/env.ml\", line 935, characters 2-86
Called from Env.find_module_components in file \"src/ocaml/typing/env.ml\", line 1028, characters 17-43
Called from Env.find_structure_components in file \"src/ocaml/typing/env.ml\", line 1038, characters 23-56
Called from Env.find_type_full in file \"src/ocaml/typing/env.ml\", line 1077, characters 15-46
Called from Env.find_type in file \"src/ocaml/typing/env.ml\" (inlined), line 1178, characters 2-24
Called from Merlin_analysis__Type_utils.print_type_with_decl.(fun) in file \"src/analysis/type_utils.ml\", line 178, characters 8-30
Called from Merlin_utils__Misc.protect_refs.(fun) in file \"src/utils/misc.ml\", line 82, characters 10-14
Re-raised at Merlin_utils__Misc.protect_refs.(fun) in file \"src/utils/misc.ml\", line 84, characters 38-45
Called from Env.with_cmis in file \"src/ocaml/typing/env.ml\" (inlined), line 3609, characters 2-47
Called from Merlin_analysis__Type_utils.print_type_with_decl in file \"src/analysis/type_utils.ml\", line 177, characters 8-65
Called from Merlin_utils__Misc.try_finally in file \"src/utils/misc.ml\", line 45, characters 8-15
Re-raised at Merlin_utils__Misc.try_finally in file \"src/utils/misc.ml\", line 62, characters 10-24
Called from Merlin_utils__Misc.protect_refs.(fun) in file \"src/utils/misc.ml\", line 82, characters 10-14
Re-raised at Merlin_utils__Misc.protect_refs.(fun) in file \"src/utils/misc.ml\", line 84, characters 38-45
Called from Persistent_env.without_cmis in file \"src/ocaml/typing/persistent_env.ml\", line 151, characters 10-109
Called from Merlin_utils__Std.let_ref in file \"src/utils/std.ml\", line 685, characters 8-12
Re-raised at Merlin_utils__Std.let_ref in file \"src/utils/std.ml\", line 687, characters 30-39
Called from Query_commands.dispatch.(fun) in file \"src/frontend/query_commands.ml\", line 337, characters 12-132
Called from Stdlib__List.mapi in file \"list.ml\", line 96, characters 20-25
Called from Dune__exe__New_commands.run in file \"src/frontend/ocamlmerlin/new/new_commands.ml\", line 65, characters 15-53
Called from Merlin_utils__Std.let_ref in file \"src/utils/std.ml\", line 685, characters 8-12
Re-raised at Merlin_utils__Std.let_ref in file \"src/utils/std.ml\", line 687, characters 30-39
Called from Merlin_utils__Misc.try_finally in file \"src/utils/misc.ml\", line 45, characters 8-15
Re-raised at Merlin_utils__Misc.try_finally in file \"src/utils/misc.ml\", line 62, characters 10-24
Called from Stdlib__Fun.protect in file \"fun.ml\", line 33, characters 8-15
Re-raised at Stdlib__Fun.protect in file \"fun.ml\", line 38, characters 6-52
Called from Mocaml.with_state in file \"src/kernel/mocaml.ml\", line 18, characters 8-38
Re-raised at Mocaml.with_state in file \"src/kernel/mocaml.ml\", line 20, characters 42-53
Called from Dune__exe__New_merlin.run.(fun) in file \"src/frontend/ocamlmerlin/new/new_merlin.ml\", line 101, characters 14-110
"