Add a --download-only flag to "opam install"

master_changes.md

@@ -21,6 +21,7 @@ New option/command/subcommand are prefixed with ◈.
 ## Install
   * The stdout of `pre-` and `post-session` hooks is now propagated to the user [#4382 @AltGr - fix #4359]
   * `post-install` hooks are allowed to modify or remove installed files, the but not add new ones. Those changes are integrated in changes file [#4388 @lefessan]
+  * ◈ Add `--download-only` flag [#4071 @Armael @rjbou - fix #4036]
 
 ## Remove
   * Fix `opam remove --autoremove <PKG>` to not autoremove unrelated packages [#4369 @AltGr - fix #4250 #4332]

src/client/opamClient.ml

@@ -1076,7 +1076,7 @@ let filter_unpinned_locally t atoms f =
     atoms
 
 let install_t t ?ask ?(ignore_conflicts=false) ?(depext_only=false)
-    atoms add_to_roots ~deps_only ~assume_built =
+    ?(download_only=false) atoms add_to_roots ~deps_only ~assume_built =
   log "INSTALL %a" (slog OpamFormula.string_of_atoms) atoms;
   let names = OpamPackage.Name.Set.of_list (List.rev_map fst atoms) in
 
@@ -1229,22 +1229,23 @@ let install_t t ?ask ?(ignore_conflicts=false) ?(depext_only=false)
       in
       let t, res =
         OpamSolution.apply ?ask t ~requested:names ?add_roots
-          ~assume_built solution in
+          ~download_only ~assume_built solution in
       t, Some (Success res)
   in
   OpamStd.Option.iter (OpamSolution.check_solution t) solution;
   t
 
 let install t ?autoupdate ?add_to_roots
     ?(deps_only=false) ?(ignore_conflicts=false) ?(assume_built=false)
-    ?(depext_only=false) names =
+    ?(download_only=false) ?(depext_only=false) names =
   let atoms = OpamSolution.sanitize_atom_list ~permissive:true t names in
   let autoupdate_atoms = match autoupdate with
     | None -> atoms
     | Some a -> OpamSolution.sanitize_atom_list ~permissive:true t a
   in
   let t = update_dev_packages_t autoupdate_atoms t in
-  install_t t ~ignore_conflicts ~depext_only atoms add_to_roots ~deps_only ~assume_built
+  install_t t atoms add_to_roots
+    ~ignore_conflicts ~depext_only ~deps_only ~download_only ~assume_built
 
 let remove_t ?ask ~autoremove ~force atoms t =
   log "REMOVE autoremove:%b %a" autoremove

src/client/opamClient.mli

@@ -51,14 +51,15 @@ val reinit:
 val install:
   rw switch_state ->
   ?autoupdate:atom list -> ?add_to_roots:bool -> ?deps_only:bool ->
-  ?ignore_conflicts:bool -> ?assume_built:bool -> ?depext_only:bool ->
-  atom list ->
+  ?ignore_conflicts:bool -> ?assume_built:bool -> ?download_only:bool ->
+  ?depext_only:bool -> atom list ->
   rw switch_state
 
 (** Low-level version of [reinstall], bypassing the package name sanitization
     and dev package update, and offering more control *)
 val install_t:
-  rw switch_state -> ?ask:bool -> ?ignore_conflicts:bool -> ?depext_only:bool ->
+  rw switch_state ->
+  ?ask:bool -> ?ignore_conflicts:bool -> ?depext_only:bool -> ?download_only:bool ->
   atom list -> bool option -> deps_only:bool -> assume_built:bool ->
   rw switch_state
 

src/client/opamCommands.ml

@@ -1515,6 +1515,10 @@ let install cli =
     mk_flag ~cli (cli_from cli2_1) ["ignore-conflicts"]
       "Used with $(b,--deps-only), ignores conflicts of given package"
   in
+  let download_only =
+    mk_flag ~cli (cli_from cli2_1) ["download-only"]
+      "Fetch the sources of the packages, but don't build or install anything."
+  in
   let restore =
     mk_flag ~cli cli_original ["restore"]
       "Attempt to restore packages that were marked for installation but have \
@@ -1545,7 +1549,7 @@ let install cli =
   let install
       global_options build_options add_to_roots deps_only ignore_conflicts
       restore destdir assume_built check recurse subpath depext_only
-      atoms_or_locals () =
+      download_only atoms_or_locals () =
     apply_global_options global_options;
     apply_build_options build_options;
     if atoms_or_locals = [] && not restore then
@@ -1606,7 +1610,7 @@ let install cli =
     let st =
       OpamClient.install st atoms
         ~autoupdate:pure_atoms ?add_to_roots ~deps_only ~ignore_conflicts
-        ~assume_built ~depext_only
+        ~assume_built ~depext_only ~download_only
     in
     match destdir with
     | None -> `Ok ()
@@ -1619,7 +1623,7 @@ let install cli =
     Term.(const install $global_options cli $build_options cli
           $add_to_roots $deps_only $ignore_conflicts $restore $destdir
           $assume_built cli $check $recurse cli $subpath cli $depext_only
-          $atom_or_local_list)
+          $download_only $atom_or_local_list)
 
 (* REMOVE *)
 let remove_doc = "Remove a list of packages."
@@ -2701,7 +2705,8 @@ let switch cli =
            if no_action || OpamFormula.satisfies_depends st.installed invariant
            then st
            else OpamClient.install_t
-               st ~ask:true [] None ~deps_only:false ~assume_built:false
+               st ~ask:true [] None
+               ~deps_only:false ~assume_built:false
          in
          OpamSwitchState.drop st;
          `Ok ())

src/client/opamSolution.ml

@@ -272,7 +272,8 @@ end
 
 (* Process the atomic actions in a graph in parallel, respecting graph order,
    and report to user. Takes a graph of atomic actions *)
-let parallel_apply t ~requested ?add_roots ~assume_built ?(force_remove=false)
+let parallel_apply t
+    ~requested ?add_roots ~assume_built ~download_only ?(force_remove=false)
     action_graph =
   log "parallel_apply";
 
@@ -418,14 +419,29 @@ let parallel_apply t ~requested ?add_roots ~assume_built ?(force_remove=false)
 
   (* 1/ process the package actions (fetch, build, installations and removals) *)
 
-  let action_graph = (* Add build actions *)
+  let action_graph = (* Add build and fetch actions *)
     let noop_remove nv =
       OpamAction.noop_remove_package t nv in
     PackageActionGraph.explicit
       ~noop_remove
       ~sources_needed:(fun p -> OpamPackage.Set.mem p sources_needed)
       action_graph
   in
+  let action_graph =
+    if download_only then
+      (* remove actions other than fetches *)
+      let g = PackageActionGraph.copy action_graph in
+      PackageActionGraph.iter_vertex (fun v ->
+          match v with
+          | `Fetch _ -> ()
+          | `Install _ | `Reinstall _ | `Change _
+          | `Remove _ | `Build _ ->
+            PackageActionGraph.remove_vertex g v
+        ) action_graph;
+      g
+    else action_graph
+  in
+
   (match OpamSolverConfig.(!r.cudf_file) with
    | None -> ()
    | Some f ->
@@ -1099,8 +1115,8 @@ let install_depexts ?(force_depext=false) ?(confirm=true) t packages =
        sys_packages)
 
 (* Apply a solution *)
-let apply ?ask t ~requested ?add_roots ?(assume_built=false) ?force_remove
-    solution =
+let apply ?ask t ~requested ?add_roots ?(assume_built=false)
+    ?(download_only=false) ?force_remove solution =
   log "apply";
   if OpamSolver.solution_is_empty solution then
     (* The current state satisfies the request contraints *)
@@ -1147,7 +1163,7 @@ let apply ?ask t ~requested ?add_roots ?(assume_built=false) ?force_remove
         OpamConsole.msg "===== %s =====\n" (OpamSolver.string_of_stats stats);
     );
     if not OpamClientConfig.(!r.show) &&
-       confirmation ?ask requested action_graph
+       (download_only || confirmation ?ask requested action_graph)
     then (
       let t =
         install_depexts t @@ OpamPackage.Set.inter
@@ -1195,7 +1211,8 @@ let apply ?ask t ~requested ?add_roots ?(assume_built=false) ?force_remove
         OpamStd.Sys.exit_because `Configuration_error;
       let t0 = t in
       let t, r =
-        parallel_apply t ~requested ?add_roots ~assume_built ?force_remove
+        parallel_apply t
+          ~requested ?add_roots ~assume_built ~download_only ?force_remove
           action_graph
       in
       let success = match r with | OK _ -> true | _ -> false in
@@ -1235,7 +1252,7 @@ let resolve t action ~orphans ?reinstall ~requested request =
   r
 
 let resolve_and_apply ?ask t action ~orphans ?reinstall ~requested ?add_roots
-    ?(assume_built=false) ?force_remove request =
+    ?(assume_built=false) ?download_only ?force_remove request =
   match resolve t action ~orphans ?reinstall ~requested request with
   | Conflicts cs ->
     log "conflict!";
@@ -1245,6 +1262,8 @@ let resolve_and_apply ?ask t action ~orphans ?reinstall ~requested ?add_roots
     t, Conflicts cs
   | Success solution ->
     let t, res =
-      apply ?ask t ~requested ?add_roots ~assume_built ?force_remove solution
+      apply ?ask t
+        ~requested ?add_roots ~assume_built ?download_only ?force_remove
+        solution
     in
     t, Success res

src/client/opamSolution.mli

@@ -34,6 +34,7 @@ val apply:
   requested:OpamPackage.Name.Set.t ->
   ?add_roots:OpamPackage.Name.Set.t ->
   ?assume_built:bool ->
+  ?download_only:bool ->
   ?force_remove:bool ->
   OpamSolver.solution ->
   rw switch_state * solution_result
@@ -52,6 +53,7 @@ val resolve_and_apply:
   requested:OpamPackage.Name.Set.t ->
   ?add_roots:OpamPackage.Name.Set.t ->
   ?assume_built:bool ->
+  ?download_only:bool ->
   ?force_remove:bool ->
   atom request ->
   rw switch_state * (solution_result, OpamCudf.conflict) result