Show an error when parsing duniverse fails

lib/views.ml

@@ -860,7 +860,7 @@ let compare_builds
     ~(build_right : Builder_db.Build.t)
     ~env_diff:(added_env, removed_env, changed_env)
     ~pkg_diff:(added_pkgs, removed_pkgs, changed_pkgs)
-    ~opam_diff:(opam_diff, version_diff, left, right, duniverse_content_diff, duniverse_left, duniverse_right)
+    ~opam_diff:(opam_diff, version_diff, left, right, duniverse)
   =
   let items, data =
     List.fold_left (fun (items, data) (id, txt, amount, code) ->
@@ -871,18 +871,24 @@ let compare_builds
           H.li [ H.a ~a:[H.a_href id_href] [txtf "%d %s" amount txt] ] :: items,
           data @ H.h3 ~a:[H.a_id id] [H.txt txt] :: code)
       ([], [])
-      [ ("opam-packages-removed", "Opam packages removed",
+      ([ ("opam-packages-removed", "Opam packages removed",
           OpamPackage.Set.cardinal left, [ H.code (packages left) ]) ;
          ("opam-packages-installede", "New opam packages installed",
           OpamPackage.Set.cardinal right, [ H.code (packages right) ]) ;
          ("opam-packages-version-diff", "Opam packages with version changes",
           List.length version_diff, [ H.code (package_diffs version_diff) ]) ;
+       ] @ (match duniverse with
+          | Ok (duniverse_left, duniverse_right, duniverse_content_diff) ->
+            [
               ("duniverse-dirs-removed", "Duniverse directories removed",
                List.length duniverse_left, [ H.code (duniverse_dirs duniverse_left) ]) ;
               ("duniverse-dirs-installed", "New duniverse directories installed",
                List.length duniverse_right, [ H.code (duniverse_dirs duniverse_right) ]) ;
               ("duniverse-dirs-content-diff", "Duniverse directories with content changes",
                List.length duniverse_content_diff, [ H.code (duniverse_diffs duniverse_content_diff) ]) ;
+            ]
+          | Error `Msg msg -> [ "duniverse-dirs-error", "Duniverse parsing error", 1,  [ H.txt msg ] ]
+        ) @ [
          ("opam-packages-opam-diff", "Opam packages with changes in their opam file",
           List.length opam_diff, opam_diffs opam_diff) ;
          ("env-removed", "Environment variables removed",
@@ -897,7 +903,7 @@ let compare_builds
           List.length added_pkgs, [ H.code (key_values added_pkgs) ]) ;
          ("pkgs-changed", "System packages changed",
           List.length changed_pkgs, [ H.code (key_value_changes changed_pkgs) ]) ;
-      ]
+       ])
   in
   layout
     ~nav:(`Comparison ((job_left, build_left), (job_right, build_right)))

opamdiff/opamdiff.ml

@@ -1,7 +1,5 @@
 module Set = OpamPackage.Set
 
-type package = OpamPackage.t
-
 let packages (switch : OpamFile.SwitchExport.t) =
   assert (Set.cardinal switch.selections.sel_pinned = 0);
   assert (Set.cardinal switch.selections.sel_compiler = 0);
@@ -58,15 +56,15 @@ let duniverse (switch : OpamFile.SwitchExport.t) =
   let root = switch.OpamFile.SwitchExport.selections.OpamTypes.sel_roots in
   if OpamPackage.Set.cardinal root = 1 then
     let root = OpamPackage.Set.choose root in
-    Option.bind
+    match OpamPackage.(Name.Map.find_opt root.name switch.OpamFile.SwitchExport.overlays) with
-      OpamPackage.(Name.Map.find_opt root.name switch.OpamFile.SwitchExport.overlays)
+    | None -> Error (`Msg "opam switch export doesn't contain the main package")
-      (fun opam ->
+    | Some opam ->
       match OpamFile.OPAM.extended opam duniverse_dir duniverse_dirs_data with
-         | None -> None
+      | None -> Ok None
-         | Some Error _ -> None
+      | Some Error e -> Error e
-         | Some Ok v -> Some v)
+      | Some Ok v -> Ok (Some v)
   else
-    None
+    Error (`Msg "not a single root package found in opam switch export")
 
 type duniverse_diff = {
   name : string ;
@@ -262,8 +260,9 @@ let compare left right =
   and right_pkgs = diff packages_right packages_left
   in
   let opam_diff = detailed_opam_diffs left right opam_diff in
-  let left_duniverse, right_duniverse, duniverse_diff =
+  let duniverse_ret =
-    duniverse_diff (duniverse left) (duniverse right)
+    match duniverse left, duniverse right with
+    | Ok l, Ok r -> Ok (duniverse_diff l r)
+    | Error _ as e, _ | _, (Error _ as e) -> e
   in
-  (opam_diff, version_diff, left_pkgs, right_pkgs,
+  (opam_diff, version_diff, left_pkgs, right_pkgs, duniverse_ret)
-   duniverse_diff, left_duniverse, right_duniverse)

opamdiff/opamdiff.mli

@@ -0,0 +1,39 @@
+type opam_diff = {
+  pkg : OpamPackage.t ;
+  build : (OpamTypes.command list * OpamTypes.command list) option ;
+  install : (OpamTypes.command list * OpamTypes.command list) option ;
+  url : (OpamFile.URL.t option * OpamFile.URL.t option) option ;
+  otherwise_equal : bool ;
+}
+
+type version_diff = {
+  name : OpamPackage.Name.t;
+  version_left : OpamPackage.Version.t;
+  version_right : OpamPackage.Version.t;
+}
+
+type duniverse_diff = {
+  name : string ;
+  urls : string * string option ;
+  hash : (OpamHash.kind * string option * string option) list ;
+}
+
+val pp_opampackage : Format.formatter -> OpamPackage.t -> unit
+
+val pp_version_diff : Format.formatter -> version_diff -> unit
+
+val pp_duniverse_diff : Format.formatter -> duniverse_diff -> unit
+
+val pp_duniverse_dir : Format.formatter -> string * string -> unit
+
+val pp_opam_diff : Format.formatter -> opam_diff -> unit
+
+val commands_to_strings : OpamTypes.command list * OpamTypes.command list -> string list * string list
+
+val opt_url_to_string : OpamFile.URL.t option * OpamFile.URL.t option -> string * string
+
+
+val compare: OpamFile.SwitchExport.t ->
+  OpamFile.SwitchExport.t ->
+  opam_diff list * version_diff list * OpamPackage.Set.t * OpamPackage.Set.t * ((string * string) list * (string * string) list * duniverse_diff list, [> `Msg of string ]) result
+