diff --git a/src/client/opamSolution.ml b/src/client/opamSolution.ml
index b32b6635666..554fa320a00 100644
--- a/src/client/opamSolution.ml
+++ b/src/client/opamSolution.ml
@@ -246,6 +246,7 @@ let display_error (n, error) =
 
 module Json = struct
   let output_request request user_action =
+    OpamTrace.with_span "Solution.Json.output_request" @@ fun () ->
     if OpamClientConfig.(!r.json_out = None) then () else
     let atoms =
       List.map (fun a -> `String (OpamFormula.short_string_of_atom a))
@@ -264,6 +265,7 @@ module Json = struct
     OpamJson.append "request" j
 
   let output_solution t solution =
+    OpamTrace.with_span "Solution.Json.output_solution" @@ fun () ->
     if OpamClientConfig.(!r.json_out = None) then () else
     match solution with
     | Success solution ->
diff --git a/src/solver/opamCudf.ml b/src/solver/opamCudf.ml
index 9f6f8390ef8..8205418799b 100644
--- a/src/solver/opamCudf.ml
+++ b/src/solver/opamCudf.ml
@@ -1524,6 +1524,7 @@ let call_external_solver ~version_map univ req =
     Dose_algo.Depsolver.Sat(None,Cudf.load_universe [])
 
 let check_request ?(explain=true) ~version_map univ req =
+  OpamTrace.with_span "Cudf.check_request" @@ fun () ->
   let chrono = OpamConsole.timer () in
   log "Checking request...";
   let result = Dose_algo.Depsolver.check_request ~explain (to_cudf univ req) in
@@ -1546,6 +1547,7 @@ let check_request ?(explain=true) ~version_map univ req =
 
 (* Return the universe in which the system has to go *)
 let get_final_universe ~version_map univ req =
+  OpamTrace.with_span "Cudf.get_final_universe" @@ fun () ->
   let fail msg =
     let f = dump_cudf_error ~version_map univ req in
     let msg =
@@ -1593,6 +1595,7 @@ let actions_of_diff (install, remove) =
   actions
 
 let resolve ~extern ~version_map universe request =
+  OpamTrace.with_span "Cudf.resolve" @@ fun () ->
   log "resolve request=%a" (slog string_of_request) request;
   let resp =
     let check () = check_request ~version_map universe request in
diff --git a/src/solver/opamSolver.ml b/src/solver/opamSolver.ml
index dbf2283f26d..8b789f4d9b8 100644
--- a/src/solver/opamSolver.ml
+++ b/src/solver/opamSolver.ml
@@ -331,6 +331,7 @@ let opam2cudf_set universe version_map packages =
       OpamCudf.Set.empty
 
 let load_cudf_packages opam_universe ?version_map opam_packages =
+  OpamTrace.with_span "Solver.load_cudf_packages" @@ fun () ->
   let chrono = OpamConsole.timer () in
   let version_map = match version_map with
     | Some vm -> vm
@@ -367,6 +368,7 @@ let map_to_cudf_universe cudf_packages_map =
 
 (* load a cudf universe from an opam one *)
 let load_cudf_universe opam_universe ?version_map opam_packages =
+  OpamTrace.with_span "Solver.load_cudf_universe" @@ fun () ->
   let load_f = load_cudf_packages opam_universe ?version_map opam_packages in
   fun ?add_invariant ?depopts ~build ~post () ->
     log "Load cudf universe (depopts:%a, build:%b, post:%b)"
@@ -436,6 +438,7 @@ let cycle_conflict ~version_map univ cycles =
   OpamCudf.cycle_conflict ~version_map univ cycles
 
 let resolve universe request =
+  OpamTrace.with_span "Solver.resolve" @@ fun () ->
   log "resolve request=%a" (slog string_of_request) request;
   let all_packages = universe.u_available ++ universe.u_installed in
   let version_map = cudf_versions_map universe in
@@ -464,6 +467,7 @@ let resolve universe request =
     opam_invariant_package version_map universe.u_invariant
   in
   let solution =
+    OpamTrace.with_span "Solver.resolve.solution" @@ fun () ->
     try
       Cudf.add_package cudf_universe invariant_pkg;
       Cudf.add_package cudf_universe deprequest_pkg;
diff --git a/src/state/opamSwitchState.ml b/src/state/opamSwitchState.ml
index a03d187b1da..07c995124fa 100644
--- a/src/state/opamSwitchState.ml
+++ b/src/state/opamSwitchState.ml
@@ -945,6 +945,7 @@ let universe st
     ?reinstall
     ~requested
     user_action =
+  OpamTrace.with_span "SwitchState.universe" @@ fun () ->
   let chrono = OpamConsole.timer () in
   let names = OpamPackage.names_of_packages requested in
   let requested_allpkgs =