Enforce dry run not changing opam root

src/client/opamAction.ml

@@ -846,7 +846,8 @@ let remove_package_aux
     | Some build_dir -> build_dir
     | None ->
       let dir = OpamPath.Switch.remove root t.switch nv in
-      if not (OpamFilename.exists_dir dir) then
+      if not OpamStateConfig.(!r.dryrun)
+      && not (OpamFilename.exists_dir dir) then
         OpamFilename.mkdir dir;
       dir
   in
@@ -907,18 +908,19 @@ let remove_package_aux
 
 (* Removes build dir and source cache of package if unneeded *)
 let cleanup_package_artefacts t nv =
-  log "Cleaning up artefacts of %a" (slog OpamPackage.to_string) nv;
+  if OpamStateConfig.(!r.dryrun) then () else
+    (log "Cleaning up artefacts of %a" (slog OpamPackage.to_string) nv;
 
-  let build_dir = OpamPath.Switch.build t.switch_global.root t.switch nv in
-  if not OpamClientConfig.(!r.keep_build_dir) then OpamFilename.rmdir build_dir;
-  let remove_dir = OpamPath.Switch.remove t.switch_global.root t.switch nv in
-  if OpamFilename.exists_dir remove_dir then OpamFilename.rmdir remove_dir;
-  let dev_dir = OpamSwitchState.source_dir t nv in
-  if not (OpamPackage.Set.mem nv t.installed) then
-    (log "Removing the local metadata";
-     OpamSwitchAction.remove_metadata t (OpamPackage.Set.singleton nv);
-     if not (OpamPackage.Set.mem nv t.pinned) then
-       OpamFilename.rmdir dev_dir)
+     let build_dir = OpamPath.Switch.build t.switch_global.root t.switch nv in
+     if not OpamClientConfig.(!r.keep_build_dir) then OpamFilename.rmdir build_dir;
+     let remove_dir = OpamPath.Switch.remove t.switch_global.root t.switch nv in
+     if OpamFilename.exists_dir remove_dir then OpamFilename.rmdir remove_dir;
+     let dev_dir = OpamSwitchState.source_dir t nv in
+     if not (OpamPackage.Set.mem nv t.installed) then
+       (log "Removing the local metadata";
+        OpamSwitchAction.remove_metadata t (OpamPackage.Set.singleton nv);
+        if not (OpamPackage.Set.mem nv t.pinned) then
+          OpamFilename.rmdir dev_dir))
 
 let sources_needed st g =
   PackageActionGraph.fold_vertex (fun act acc ->

src/client/opamClient.ml

@@ -2427,10 +2427,13 @@ let remove_t ?ask ~autoremove ~force ?(formula=OpamFormula.Empty) atoms t =
           let nv = OpamPackage.max_version candidates (fst atom) in
           OpamConsole.note "Forcing removal of (uninstalled) %s"
             (OpamPackage.to_string nv);
-          let d = OpamPath.Switch.remove t.switch_global.root t.switch nv in
-          OpamFilename.rmdir d;
-          OpamFilename.mkdir d;
-          OpamProcess.Job.run (OpamAction.remove_package t nv);
+          if OpamStateConfig.(!r.dryrun) then
+            OpamProcess.Job.dry_run (OpamAction.remove_package t nv)
+          else
+            (let d = OpamPath.Switch.remove t.switch_global.root t.switch nv in
+             OpamFilename.rmdir d;
+             OpamFilename.mkdir d;
+             OpamProcess.Job.run (OpamAction.remove_package t nv));
           OpamAction.cleanup_package_artefacts t nv;
           false
         with Not_found ->

src/client/opamCommands.ml

@@ -3084,21 +3084,22 @@ let switch cli =
       end;
       `Ok ()
     | Some `remove, switches ->
-      OpamGlobalState.with_ `Lock_write @@ fun gt ->
-      let _gt =
-        List.fold_left
-          (fun gt switch ->
-             let opam_dir = OpamFilename.Op.(
-                 OpamFilename.Dir.of_string switch / OpamSwitch.external_dirname
-               ) in
-             if OpamFilename.is_symlink_dir opam_dir then
-               (OpamFilename.rmdir opam_dir;
-                gt)
-             else OpamSwitchCommand.remove gt (OpamSwitch.of_string switch))
-          gt
-          switches
-      in
-      `Ok ()
+      if OpamStateConfig.(!r.dryrun) then `Ok () else
+        OpamGlobalState.with_ `Lock_write @@ fun gt ->
+        let _gt =
+          List.fold_left
+            (fun gt switch ->
+               let opam_dir = OpamFilename.Op.(
+                   OpamFilename.Dir.of_string switch / OpamSwitch.external_dirname
+                 ) in
+               if OpamFilename.is_symlink_dir opam_dir then
+                 (OpamFilename.rmdir opam_dir;
+                  gt)
+               else OpamSwitchCommand.remove gt (OpamSwitch.of_string switch))
+            gt
+            switches
+        in
+        `Ok ()
     | Some `reinstall, switch ->
       let switch = match switch with
         | [sw] -> OpamSwitch.of_string sw

src/client/opamPinCommand.ml

@@ -66,7 +66,12 @@ exception Fetch_Fail of string
 
 let get_source_definition ?version ?subpath ?locked st nv url =
   let root = st.switch_global.root in
-  let srcdir = OpamPath.Switch.pinned_package root st.switch nv.name in
+  let srcdir =
+    if OpamStateConfig.(!r.dryrun) then
+      OpamFilename.mk_tmp_dir ()
+    else
+      OpamPath.Switch.pinned_package root st.switch nv.name
+  in
   let fix opam =
     OpamFile.OPAM.with_url url @@
     (match version with
@@ -374,7 +379,12 @@ let fetch_all_pins st ?working_dir pins =
     let command pinned =
       let { pinned_name = name; pinned_url = url;
             pinned_subpath = subpath; _ } = pinned in
-      let srcdir = OpamPath.Switch.pinned_package root st.switch name in
+      let srcdir =
+        if OpamStateConfig.(!r.dryrun) then
+          OpamFilename.mk_tmp_dir ()
+        else
+          OpamPath.Switch.pinned_package root st.switch name
+      in
       let name = OpamPackage.Name.to_string name in
       OpamProcess.Job.Op.(
         OpamRepository.pull_tree ~cache_dir ?subpath ?working_dir
@@ -620,6 +630,7 @@ and source_pin
 
     let opam = copy_files st opam in
 
+    if not OpamStateConfig.(!r.dryrun) then
     OpamFile.OPAM.write_with_preserved_format
       ?format_from:(OpamPinned.orig_opam_file st name opam)
       (OpamPath.Switch.Overlay.opam st.switch_global.root st.switch nv.name)
@@ -699,11 +710,12 @@ let unpin st names =
   log "unpin %a"
     (slog @@ OpamStd.List.concat_map " " OpamPackage.Name.to_string) names;
   List.fold_left (fun st name ->
-      OpamFilename.rmdir
-        (OpamPath.Switch.pinned_package st.switch_global.root st.switch name);
-      OpamFilename.rmdir
-        (OpamPath.Switch.Overlay.package
-           st.switch_global.root st.switch name);
+      if not OpamStateConfig.(!r.dryrun) then
+        (OpamFilename.rmdir
+           (OpamPath.Switch.pinned_package st.switch_global.root st.switch name);
+         OpamFilename.rmdir
+           (OpamPath.Switch.Overlay.package
+              st.switch_global.root st.switch name));
       match OpamPinned.package_opt st name with
       | Some nv ->
         let pin_str =

src/client/opamSolution.ml

@@ -648,7 +648,8 @@ let parallel_apply t
         try true, OpamPackage.Map.find nv inplace
         with Not_found ->
           let dir = OpamPath.Switch.build t.switch_global.root t.switch nv in
-          if not OpamClientConfig.(!r.reuse_build_dir) then
+          if not OpamClientConfig.(!r.reuse_build_dir)
+          && not OpamStateConfig.(!r.dryrun) then
             OpamFilename.rmdir dir;
           false, dir
       in
@@ -659,10 +660,12 @@ let parallel_apply t
         OpamStateConfig.(!r.dev_setup) && found
       in
       let source_dir = source_dir nv in
-      (if OpamFilename.exists_dir source_dir
+      (if OpamStateConfig.(!r.dryrun) then () else
+       if OpamFilename.exists_dir source_dir
        then (if not is_inplace then
                OpamFilename.copy_dir ~src:source_dir ~dst:build_dir)
-       else OpamFilename.mkdir build_dir;
+       else
+         OpamFilename.mkdir build_dir;
        OpamAction.prepare_package_source t nv build_dir @@+ function
        | Some exn -> store_time (); Done (`Exception exn)
        | None ->
@@ -688,7 +691,8 @@ let parallel_apply t
          store_time ();
          Done (`Exception exn))
     | `Remove nv ->
-      (if OpamAction.removal_needs_download t nv then
+      (if not OpamStateConfig.(!r.dryrun)
+       && OpamAction.removal_needs_download t nv then
          let d = OpamPath.Switch.remove t.switch_global.root t.switch nv in
          OpamFilename.rmdir d;
          let source_dir = source_dir nv in
@@ -823,31 +827,32 @@ let parallel_apply t
   (* 2/ Display errors and finalize *)
 
   let save_installed_cache failed =
-    OpamSwitchState.Installed_cache.save
-      (OpamPath.Switch.installed_opams_cache t.switch_global.root t.switch)
-      (OpamPackage.Set.fold (fun nv opams ->
-           (* NOTE: We need to know whether an action was successful
-              or not to know which version of the opam file to store
-              in the case: the previous one if it failed, or the new
-              one if it succeeded. *)
-           let pkg_failed =
-             List.exists (function
-                 | `Fetch ps -> List.for_all (OpamPackage.equal nv) ps
-                 | `Build p | `Change (_, _, p) | `Install p
-                 | `Reinstall p | `Remove p -> OpamPackage.equal nv p)
-               failed
-           in
-           let add_to_opams opam =
-             let opam = OpamFile.OPAM.with_metadata_dir None opam in
-             OpamPackage.Map.add nv opam opams
-           in
-           if pkg_failed then
-             match OpamPackage.Map.find_opt nv t.installed_opams with
-             | None -> opams
-             | Some opam -> add_to_opams opam
-           else
-             add_to_opams (OpamSwitchState.opam t nv))
-          t.installed OpamPackage.Map.empty);
+    if not OpamStateConfig.(!r.dryrun) then
+      OpamSwitchState.Installed_cache.save
+        (OpamPath.Switch.installed_opams_cache t.switch_global.root t.switch)
+        (OpamPackage.Set.fold (fun nv opams ->
+             (* NOTE: We need to know whether an action was successful
+                or not to know which version of the opam file to store
+                in the case: the previous one if it failed, or the new
+                one if it succeeded. *)
+             let pkg_failed =
+               List.exists (function
+                   | `Fetch ps -> List.for_all (OpamPackage.equal nv) ps
+                   | `Build p | `Change (_, _, p) | `Install p
+                   | `Reinstall p | `Remove p -> OpamPackage.equal nv p)
+                 failed
+             in
+             let add_to_opams opam =
+               let opam = OpamFile.OPAM.with_metadata_dir None opam in
+               OpamPackage.Map.add nv opam opams
+             in
+             if pkg_failed then
+               match OpamPackage.Map.find_opt nv t.installed_opams with
+               | None -> opams
+               | Some opam -> add_to_opams opam
+             else
+               add_to_opams (OpamSwitchState.opam t nv))
+            t.installed OpamPackage.Map.empty);
   in
   begin match action_results with
   | `Exception _ | `Error Aborted -> ()

src/state/opamSwitchAction.ml

@@ -117,7 +117,8 @@ let add_to_reinstall st ~unpinned_only packages =
   let reinstall =
     current_reinstall ++ add_reinst_packages
   in
-  if OpamPackage.Set.equal current_reinstall reinstall then ()
+  if OpamStateConfig.(!r.dryrun)
+  || OpamPackage.Set.equal current_reinstall reinstall then ()
   else if OpamPackage.Set.is_empty reinstall then
     OpamFilename.remove (OpamFile.filename reinstall_file)
   else

src/state/opamSwitchState.ml

@@ -419,7 +419,7 @@ let load lock_kind gt rt switch =
       let switch_config =
         {switch_config with invariant = Some invariant; opam_version}
       in
-      if lock_kind = `Lock_write then
+      if lock_kind = `Lock_write && not OpamStateConfig.(!r.dryrun) then
         OpamFile.Switch_config.write
           (OpamPath.Switch.switch_config gt.root switch)
           switch_config;
@@ -1285,7 +1285,7 @@ let update_pin nv opam st =
   { st with sys_packages; available_packages }
 
 let do_backup lock st = match lock with
-  | `Lock_write ->
+  | `Lock_write when not OpamStateConfig.(!r.dryrun) ->
     let file = OpamPath.Switch.backup st.switch_global.root st.switch in
     let previous_selections = selections st in
     OpamFile.SwitchSelections.write file previous_selections;

src/state/opamUpdate.ml

@@ -283,7 +283,24 @@ let pinned_package st ?version ?(autolock=false) ?(working_dir=false) name =
                   Filename.dir_sep ^ OpamFilename.SubPath.to_string sp) subpath))
     @@+ fun () ->
     (* Do the update *)
+    let srcdir0 = srcdir in
+    let srcdir, srcdir_find =
+      if OpamStateConfig.(!r.dryrun) then
+        let tmpdir = OpamFilename.mk_tmp_dir () in
+        tmpdir, OpamFilename.SubPath.(tmpdir /? subpath)
+      else
+        srcdir, srcdir_find
+    in
     fetch_dev_package urlf srcdir ~working_dir ?subpath nv @@+ fun result ->
+    let result =
+      match OpamStateConfig.(!r.dryrun), result with
+      | true, Result () ->
+        let base f = OpamFilename.Base.of_string (OpamFilename.Dir.to_string f) in
+        (match OpamRepositoryBackend.get_diff (OpamFilename.Dir.of_string "/") (base srcdir) (base srcdir0) with
+         | Some _ -> Result ()
+         | None -> Up_to_date ())
+      | _, (Result () | Up_to_date () | Not_available _) -> result
+    in
     let new_source_opam =
       OpamPinned.find_opam_file_in_source ?locked name srcdir_find
       >>= fun (f, lock) ->
@@ -332,16 +349,6 @@ let pinned_package st ?version ?(autolock=false) ?(working_dir=false) name =
       | Some a, Some b -> not (equal_opam a b)
     in
     let save_overlay opam =
-      OpamFilename.mkdir overlay_dir;
-      let opam_file = OpamPath.Switch.Overlay.opam root st.switch name in
-      List.iter OpamFilename.remove
-        OpamPath.Switch.Overlay.([
-            OpamFile.filename opam_file;
-            OpamFile.filename (url root st.switch name);
-            OpamFile.filename (descr root st.switch name);
-          ]);
-      let files_dir = OpamPath.Switch.Overlay.files root st.switch name in
-      OpamFilename.rmdir files_dir;
       let opam =
         OpamFile.OPAM.with_url urlf @@
         OpamFile.OPAM.with_name name opam
@@ -351,19 +358,30 @@ let pinned_package st ?version ?(autolock=false) ?(working_dir=false) name =
         then OpamFile.OPAM.with_version version opam
         else opam
       in
-      List.iter (fun (rel_file, content, hash) ->
-          match content with
-          | Some (lazy content) when OpamHash.check_string content hash ->
-            OpamFilename.write (OpamFilename.create files_dir rel_file) content
-          | None | Some _ ->
-            OpamConsole.warning "Ignoring file %s with invalid hash"
-              (OpamFilename.Base.to_string rel_file))
-        (OpamFile.OPAM.get_extra_files
-           ~get_repo_files:(OpamRepositoryState.get_repo_files st.switch_repos)
-           opam);
-      OpamFile.OPAM.write opam_file
-        (OpamFile.OPAM.with_extra_files_opt None opam);
-      opam
+      if OpamStateConfig.(!r.dryrun) then opam else
+        (OpamFilename.mkdir overlay_dir;
+         let opam_file = OpamPath.Switch.Overlay.opam root st.switch name in
+         List.iter OpamFilename.remove
+           OpamPath.Switch.Overlay.([
+               OpamFile.filename opam_file;
+               OpamFile.filename (url root st.switch name);
+               OpamFile.filename (descr root st.switch name);
+             ]);
+         let files_dir = OpamPath.Switch.Overlay.files root st.switch name in
+         OpamFilename.rmdir files_dir;
+         List.iter (fun (rel_file, content, hash) ->
+             match content with
+             | Some (lazy content) when OpamHash.check_string content hash ->
+               OpamFilename.write (OpamFilename.create files_dir rel_file) content
+             | None | Some _ ->
+               OpamConsole.warning "Ignoring file %s with invalid hash"
+                 (OpamFilename.Base.to_string rel_file))
+           (OpamFile.OPAM.get_extra_files
+              ~get_repo_files:(OpamRepositoryState.get_repo_files st.switch_repos)
+              opam);
+         OpamFile.OPAM.write opam_file
+           (OpamFile.OPAM.with_extra_files_opt None opam);
+         opam)
     in
     match result, new_source_opam with
     | Result _, Some new_opam