From 897fddc9620a9adeac11a96e0ceb39d4c166d63e Mon Sep 17 00:00:00 2001
From: David Allsopp <david.allsopp@metastack.com>
Date: Tue, 12 Mar 2024 12:35:01 +0000
Subject: [PATCH] Feed it

---
 src/solver/opamCudf.ml   |  1 +
 src/solver/opamCudf.mli  |  3 +++
 src/solver/opamSolver.ml | 22 ++++++++++++++--------
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/solver/opamCudf.ml b/src/solver/opamCudf.ml
index 9318ab39152..3e57a4b24e5 100644
--- a/src/solver/opamCudf.ml
+++ b/src/solver/opamCudf.ml
@@ -22,6 +22,7 @@ let s_reinstall = "reinstall"
 let s_installed_root = "installed-root"
 let s_pinned = "pinned"
 let s_version_lag = "version-lag"
+let s_avoid_version = "avoid-version"
 
 let opam_invariant_package_name =
   Dose_common.CudfAdd.encode "=opam-invariant"
diff --git a/src/solver/opamCudf.mli b/src/solver/opamCudf.mli
index 278be48c1c3..25fa2c8ed0a 100644
--- a/src/solver/opamCudf.mli
+++ b/src/solver/opamCudf.mli
@@ -186,6 +186,9 @@ val s_pinned: string
 (** the number of versions of the package since this one, cubed *)
 val s_version_lag: string
 
+(** the avoid-version flag *)
+val s_avoid_version: string
+
 (** valid cudf name for the dummy package used for enforcing opam's switch
     invariants *)
 val opam_invariant_package_name: string
diff --git a/src/solver/opamSolver.ml b/src/solver/opamSolver.ml
index bd68b18327f..0a501d02dd0 100644
--- a/src/solver/opamSolver.ml
+++ b/src/solver/opamSolver.ml
@@ -167,15 +167,25 @@ let opam2cudf_map universe version_map packages =
     OpamPackage.Set.fold (fun nv -> OpamPackage.Map.add nv true)
       (packages %% set) OpamPackage.Map.empty
   in
+  let avoid_versions =
+    OpamStd.Option.default OpamPackage.Set.empty @@
+    OpamStd.List.assoc_opt String.equal "avoid-version" universe.u_attrs
+  in
   let base_map =
     OpamPackage.Set.fold (fun nv ->
+        let pkg_extra = [
+          OpamCudf.s_source, `String(OpamPackage.name_to_string nv);
+          OpamCudf.s_source_number, `String(OpamPackage.version_to_string nv);
+        ] in
+        let pkg_extra =
+          if OpamPackage.Set.mem nv avoid_versions then
+            (OpamCudf.s_avoid_version, `Bool true)::pkg_extra
+          else
+            pkg_extra in
         OpamPackage.Map.add nv
           { Cudf.default_package with
             Cudf.package = name_to_cudf nv.name;
-            pkg_extra = [
-              OpamCudf.s_source, `String(OpamPackage.name_to_string nv);
-              OpamCudf.s_source_number, `String(OpamPackage.version_to_string nv);
-            ];
+            pkg_extra;
           })
       packages OpamPackage.Map.empty
   in
@@ -188,10 +198,6 @@ let opam2cudf_map universe version_map packages =
   let reinstall_map = set_to_bool_map universe.u_reinstall in
   let installed_root_map = set_to_bool_map universe.u_installed_roots in
   let pinned_to_current_version_map = set_to_bool_map universe.u_pinned in
-  let avoid_versions =
-    OpamStd.Option.default OpamPackage.Set.empty @@
-    OpamStd.List.assoc_opt String.equal "avoid-version" universe.u_attrs
-  in
   let version_lag_map =
     OpamPackage.Name.Map.fold (fun name version_set acc ->
         let nvers, vs =