diff --git a/.github/workflows/common.yml b/.github/workflows/common.yml
index 946bcaac1..8ee21d6d0 100644
--- a/.github/workflows/common.yml
+++ b/.github/workflows/common.yml
@@ -81,6 +81,8 @@ jobs:
   build-and-test:
     env:
       QCHECK_MSG_INTERVAL:      '60'
+      TIMELOGDIR:               ${{ github.workspace }}
+      TIMEOUT:                  ${{ inputs.timeout }}
       DUNE_PROFILE:             ${{ inputs.dune_profile }}
       OCAMLRUNPARAM:            ${{ inputs.runparam }}
       ONLY_TEST:                ${{ inputs.only_test }}
@@ -118,6 +120,10 @@ jobs:
             echo "LDFLAGS=-L/usr/lib/i386-linux-gnu/" >> $GITHUB_ENV
           fi
 
+          # Compute a deadline to respect time-out
+          echo "DEADLINE=$(date -d "now + $((TIMEOUT - 3)) minutes" +%s)" >> "$GITHUB_ENV"
+          cat "$GITHUB_ENV"
+
           # Generate an OPAM config for a custom compiler
           if [ -n "$CUSTOM_COMPILER_VERSION" ]; then
             if [ -z "$CUSTOM_COMPILER_SRC" ]; then
@@ -203,6 +209,7 @@ jobs:
           echo "OPAMJOBS=1" >> $GITHUB_ENV
 
       - name: Install Multicore Tests dependencies
+        id: dependencies
         run: |
           opam install . --deps-only --with-test
 
@@ -272,3 +279,7 @@ jobs:
           }
           echo "Test failed $failures times"
         if: env.ONLY_TEST != '' && runner.os == 'Windows'
+
+      - name: Summarize test run times
+        run: opam exec -- dune build @cat-times
+        if: "success() || (failure() && steps.dependencies.conclusion == 'success')"
diff --git a/src/array/dune b/src/array/dune
index 91892dbe7..8dd985ebb 100644
--- a/src/array/dune
+++ b/src/array/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 (test
@@ -16,7 +16,7 @@
  (flags (:standard -w -27))
  (libraries qcheck-lin.domain)
  (preprocess (pps ppx_deriving_qcheck ppx_deriving.show ppx_deriving.eq))
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests.exe}))
  (action (echo "Skipping src/array/%{test} from the test suite\n\n"))
 )
 
@@ -25,5 +25,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/atomic/dune b/src/atomic/dune
index b9ab37456..8855e19eb 100644
--- a/src/atomic/dune
+++ b/src/atomic/dune
@@ -8,7 +8,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 ;; Linearization tests of Atomic, utilizing ppx_deriving_qcheck
@@ -20,7 +20,7 @@
  (flags (:standard -w -27))
  (libraries qcheck-lin.domain)
  (preprocess (pps ppx_deriving_qcheck ppx_deriving.show ppx_deriving.eq))
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests.exe}))
  (action (echo "Skipping src/atomic/%{test} from the test suite\n\n"))
 )
 
@@ -29,5 +29,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/bigarray/dune b/src/bigarray/dune
index 5016d76d8..4157c035b 100644
--- a/src/bigarray/dune
+++ b/src/bigarray/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:stm_tests.exe}))
  (action (echo "Skipping src/bigarray/%{test} from the test suite\n\n"))
 )
 
@@ -15,5 +15,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/buffer/dune b/src/buffer/dune
index 725058f70..e643c2e1c 100644
--- a/src/buffer/dune
+++ b/src/buffer/dune
@@ -6,5 +6,5 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
diff --git a/src/bytes/dune b/src/bytes/dune
index d20e3c6e8..c5359d768 100644
--- a/src/bytes/dune
+++ b/src/bytes/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 (test
@@ -14,5 +14,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain qcheck-lin.thread)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/domain/dune b/src/domain/dune
index 35630838d..239bbf820 100644
--- a/src/domain/dune
+++ b/src/domain/dune
@@ -8,7 +8,7 @@
  (package multicoretests)
  (libraries util qcheck-core qcheck-core.runner)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:domain_joingraph.exe}))
 )
 
 (test
@@ -17,5 +17,5 @@
  (package multicoretests)
  (libraries util qcheck-core qcheck-core.runner)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:domain_spawntree.exe}))
 )
diff --git a/src/dynlink/dune b/src/dynlink/dune
index 34cb1679a..eab7e453d 100644
--- a/src/dynlink/dune
+++ b/src/dynlink/dune
@@ -15,5 +15,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain dynlink libA libB)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/ephemeron/dune b/src/ephemeron/dune
index 27f1f7f1b..5a2927ae4 100644
--- a/src/ephemeron/dune
+++ b/src/ephemeron/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 (test
@@ -14,5 +14,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain qcheck-lin.thread)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/floatarray/dune b/src/floatarray/dune
index eb4811ff2..ecca151ba 100644
--- a/src/floatarray/dune
+++ b/src/floatarray/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 (test
@@ -14,5 +14,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/hashtbl/dune b/src/hashtbl/dune
index b3373a377..40087580a 100644
--- a/src/hashtbl/dune
+++ b/src/hashtbl/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 (test
@@ -16,7 +16,7 @@
  (flags (:standard -w -27))
  (libraries qcheck-lin.domain)
  (preprocess (pps ppx_deriving_qcheck ppx_deriving.show ppx_deriving.eq))
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests.exe}))
  (action (echo "Skipping src/hashtbl/%{test} from the test suite\n\n"))
 )
 
@@ -25,5 +25,5 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
diff --git a/src/io/dune b/src/io/dune
index 4985a5b0d..7362036a8 100644
--- a/src/io/dune
+++ b/src/io/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  ;(flags (:standard -w -27))
  (libraries qcheck-lin.domain)
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests.exe}))
  (action (echo "Skipping src/io/%{test} from the test suite\n\n"))
 )
 
@@ -23,7 +23,7 @@
  (package multicoretests)
  ;(flags (:standard -w -27))
  (libraries qcheck-lin.domain lin_tests_dsl_common_io)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl_domain.exe}))
 )
 
 (test
@@ -32,6 +32,6 @@
  (package multicoretests)
  ;(flags (:standard -w -27))
  (libraries qcheck-lin.thread lin_tests_dsl_common_io)
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests_dsl_thread.exe}))
  (action (echo "Skipping src/io/%{test} from the test suite\n\n"))
 )
diff --git a/src/lazy/dune b/src/lazy/dune
index 937d13dd8..9ca6374cc 100644
--- a/src/lazy/dune
+++ b/src/lazy/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 (test
@@ -15,7 +15,7 @@
  (package multicoretests)
  (libraries qcheck-lin.domain)
  (preprocess (pps ppx_deriving_qcheck ppx_deriving.show ppx_deriving.eq))
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests.exe}))
  (action (echo "Skipping src/lazy/%{test} from the test suite\n\n"))
 )
 
@@ -24,6 +24,6 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests_dsl.exe}))
  (action (echo "Skipping src/lazy/%{test} from the test suite\n\n"))
 )
diff --git a/src/neg_tests/dune b/src/neg_tests/dune
index 7c36a7454..1529e7c15 100644
--- a/src/neg_tests/dune
+++ b/src/neg_tests/dune
@@ -13,7 +13,7 @@
  (modules stm_tests_sequential_ref)
  (package multicoretests)
  (libraries stm_tests_spec_ref qcheck-stm.sequential)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests_sequential_ref.exe}))
 )
 
 (test
@@ -21,7 +21,7 @@
  (modules stm_tests_domain_ref)
  (package multicoretests)
  (libraries stm_tests_spec_ref qcheck-stm.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests_domain_ref.exe}))
 )
 
 (test
@@ -29,7 +29,7 @@
  (modules stm_tests_thread_ref)
  (package multicoretests)
  (libraries stm_tests_spec_ref qcheck-stm.thread)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests_thread_ref.exe}))
 )
 
 (library
@@ -44,7 +44,7 @@
  (package multicoretests)
  (libraries CList qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests_conclist.exe}))
 )
 
 ;; Linearization tests of ref and Clist with Lin
@@ -70,7 +70,7 @@
  (package multicoretests)
  (flags (:standard -w -27))
  (libraries lin_tests_dsl_common)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl_domain.exe}))
 )
 
 (test
@@ -79,7 +79,7 @@
  (package multicoretests)
  (flags (:standard -w -27))
  (libraries lin_tests_dsl_common qcheck-lin.thread)
- ; (action (run %{test} --verbose))
+ ; (action (run runner %{dep:lin_tests_dsl_thread.exe}))
  (action (echo "Skipping src/neg_tests/%{test} from the test suite\n\n"))
 )
 
@@ -89,7 +89,7 @@
  (package multicoretests)
  (flags (:standard -w -27))
  (libraries lin_tests_dsl_common qcheck-lin.effect)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl_effect.exe}))
 )
 
 ;; Linearization tests of ref and Clist with Lin.Internal
@@ -100,17 +100,26 @@
  (package multicoretests)
  (flags (:standard -w -27))
  (libraries lin_tests_common)
-  ; (action (run %{test} --verbose))
+  ; (action (run runner %{dep:lin_tests_domain.exe}))
  (action (echo "Skipping src/neg_tests/%{test} from the test suite\n\n"))
 )
 
-(tests
- (names lin_tests_thread_ref lin_tests_thread_conclist)
- (modules lin_tests_thread_ref lin_tests_thread_conclist)
+(test
+ (name lin_tests_thread_ref)
+ (modules lin_tests_thread_ref)
+ (package multicoretests)
+ (flags (:standard -w -27))
+ (libraries lin_tests_common qcheck-lin.thread)
+ (action (run runner %{dep:lin_tests_thread_ref.exe}))
+)
+
+(test
+ (name lin_tests_thread_conclist)
+ (modules lin_tests_thread_conclist)
  (package multicoretests)
  (flags (:standard -w -27))
  (libraries lin_tests_common qcheck-lin.thread)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_thread_conclist.exe}))
 )
 
 (test
@@ -120,6 +129,6 @@
  (flags (:standard -w -27))
  (libraries lin_tests_common qcheck-lin.effect)
  (preprocess (pps ppx_deriving.show ppx_deriving.eq))
-  ; (action (run ./%{deps} --verbose))
+  ; (action (run runner %{dep:lin_tests_effect.exe}))
  (action (echo "Skipping src/neg_tests/%{test} from the test suite\n\n"))
 )
diff --git a/src/queue/dune b/src/queue/dune
index 246e7bf06..77005663e 100644
--- a/src/queue/dune
+++ b/src/queue/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (flags (:standard -w -27))
  (libraries qcheck-lin.domain qcheck-lin.thread)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
 
 (test
@@ -16,6 +16,6 @@
  (flags (:standard -w -27))
  (libraries qcheck-lin.domain qcheck-lin.thread)
  (preprocess (pps ppx_deriving_qcheck ppx_deriving.show ppx_deriving.eq))
- ;(action (run %{test} --verbose))
+ ;(action (run runner %{dep:lin_tests.exe}))
  (action (echo "Skipping src/queue/%{test} from the test suite\n\n"))
 )
diff --git a/src/semaphore/dune b/src/semaphore/dune
index 6e4d5e285..c2cac616f 100644
--- a/src/semaphore/dune
+++ b/src/semaphore/dune
@@ -6,5 +6,5 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
diff --git a/src/stack/dune b/src/stack/dune
index ac02856a6..a25a0f0da 100644
--- a/src/stack/dune
+++ b/src/stack/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (flags (:standard -w -27))
  (libraries qcheck-lin.domain qcheck-lin.thread)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
 
 (test
@@ -16,7 +16,7 @@
  (flags (:standard -w -27))
  (libraries qcheck-lin.domain qcheck-lin.thread)
  (preprocess (pps ppx_deriving_qcheck ppx_deriving.show ppx_deriving.eq))
-  ; (action (run %{test} --verbose))
+  ; (action (run runner %{dep:lin_tests.exe}))
  (action (echo "Skipping src/stack/%{test} from the test suite\n\n"))
 )
 
diff --git a/src/sys/dune b/src/sys/dune
index bac13a868..bf9713f1f 100644
--- a/src/sys/dune
+++ b/src/sys/dune
@@ -6,5 +6,5 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
diff --git a/src/thread/dune b/src/thread/dune
index a2d5087a0..dc6c9d26c 100644
--- a/src/thread/dune
+++ b/src/thread/dune
@@ -8,7 +8,7 @@
  (package multicoretests)
  (libraries threads qcheck-core util)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:thread_joingraph.exe}))
 )
 
 (test
@@ -17,5 +17,5 @@
  (package multicoretests)
  (libraries threads qcheck-core util)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:thread_createtree.exe}))
 )
diff --git a/src/threadomain/dune b/src/threadomain/dune
index 2034a3e5e..be0d8fbcc 100644
--- a/src/threadomain/dune
+++ b/src/threadomain/dune
@@ -6,5 +6,5 @@
  (package multicoretests)
  (libraries util qcheck-core threads)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:threadomain.exe}))
 )
diff --git a/src/weak/dune b/src/weak/dune
index d054148f3..9a6a2474a 100644
--- a/src/weak/dune
+++ b/src/weak/dune
@@ -6,7 +6,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests.exe}))
 )
 
 (test
@@ -15,7 +15,7 @@
  (package multicoretests)
  (libraries qcheck-stm.sequential qcheck-stm.domain)
  (preprocess (pps ppx_deriving.show))
- (action (run %{test} --verbose))
+ (action (run runner %{dep:stm_tests_hashset.exe}))
 )
 
 (test
@@ -23,7 +23,7 @@
  (modules lin_tests_dsl)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl.exe}))
 )
 
 (test
@@ -31,5 +31,5 @@
  (modules lin_tests_dsl_hashset)
  (package multicoretests)
  (libraries qcheck-lin.domain)
- (action (run %{test} --verbose))
+ (action (run runner %{dep:lin_tests_dsl_hashset.exe}))
 )
diff --git a/tools/dune b/tools/dune
new file mode 100644
index 000000000..d1da59de1
--- /dev/null
+++ b/tools/dune
@@ -0,0 +1,14 @@
+(executable
+ (name runner)
+ (public_name runner)
+ (package multicoretests)
+ (libraries unix))
+
+(rule
+ (action
+  (write-file times.log "Dummy file for missing timing data")))
+
+(rule
+ (alias cat-times)
+ (action
+  (cat %{env:TIMELOGDIR=.}/times.log)))
diff --git a/tools/runner.ml b/tools/runner.ml
new file mode 100644
index 000000000..717f842bc
--- /dev/null
+++ b/tools/runner.ml
@@ -0,0 +1,189 @@
+(* Custom runner for the tests so that:
+   - error codes on Windows are turned back into their Unix meaninrgs
+   - anchors are added to CI logs with relevant information *)
+
+let use_github_anchors = Sys.getenv_opt "CI" = Some "true"
+
+let signals =
+  let open Sys in
+  [
+    (sigabrt, "ABRT");
+    (sigalrm, "ALRM");
+    (sigfpe, "FPE");
+    (sighup, "HUP");
+    (sigill, "ILL");
+    (sigint, "INT");
+    (sigkill, "KILL");
+    (sigpipe, "PIPE");
+    (sigquit, "QUIT");
+    (sigsegv, "SEGV");
+    (sigterm, "TERM");
+    (sigusr1, "USR1");
+    (sigusr2, "USR2");
+    (sigchld, "CHLD");
+    (sigcont, "CONT");
+    (sigstop, "STOP");
+    (sigtstp, "TSTP");
+    (sigttin, "TTIN");
+    (sigttou, "TTOU");
+    (sigvtalrm, "VTALRM");
+    (sigprof, "PROF");
+    (sigbus, "BUS");
+    (sigpoll, "POLL");
+    (sigsys, "SYS");
+    (sigtrap, "TRAP");
+    (sigurg, "URG");
+    (sigxcpu, "XCPU");
+    (sigxfsz, "XFSZ");
+  ]
+
+let error fmt cmd msg =
+  if use_github_anchors then
+    Format.fprintf fmt "\n::error title=%s in %s::%s in %s\n%!" msg cmd msg cmd
+  else Format.fprintf fmt "\nError: %s in %s\n%!" msg cmd
+
+let warning fmt cmd msg =
+  if use_github_anchors then
+    Format.fprintf fmt "\n::warning title=%s in %s::%s in %s\n%!" msg cmd msg
+      cmd
+  else Format.fprintf fmt "\nWarning: %s in %s\n%!" msg cmd
+
+let timed_out = Atomic.make false
+
+let pp_status_unix fmt cmd status =
+  let open Unix in
+  let success = ref false in
+  (match status with
+  | WEXITED 0 -> success := true
+  | WEXITED s -> error fmt cmd (Printf.sprintf "Exit %d" s)
+  | WSIGNALED s when Atomic.get timed_out && (s = Sys.sigkill || s = Sys.sigterm)
+    ->
+      warning fmt cmd "Deadline reached, test interrupted";
+      (* We nevertheless want the test to globally succeed *)
+      success := true
+  | WSIGNALED s ->
+      let msg =
+        match List.assoc_opt s signals with
+        | Some signal -> "Signal " ^ signal
+        | None -> Printf.sprintf "Unknown signal %d" s
+      in
+      error fmt cmd msg
+  | WSTOPPED s ->
+      let msg =
+        match List.assoc_opt s signals with
+        | Some signal -> "Stop with signal " ^ signal
+        | None -> Printf.sprintf "Stop with unknown signal %d" s
+      in
+      error fmt cmd msg);
+  !success
+
+(* Under Windows, there is no such thing as terminating due to a
+   signal, so the WSIGNALED and WSTOPPED cases are dead code.
+
+   The strategy is to use conventional exit values (which are 32-bit,
+   not just 8-bit like on Unix) to describe the cause.
+   The documentation of ”NTSTATUS Values” list {e many} cases, too
+   many to handle them all. This is where the value akin to SEGV comes
+   from. Other special cases will be caught as they appear.
+
+   The value used to match ABRT comes from the code of the abort
+   function in the standard library.
+
+   {{:https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/596a1078-e883-4972-9bbc-49e60bebca55}NTSTATUS Values}
+*)
+let pp_status_win fmt cmd status =
+  let open Unix in
+  (match status with
+  | WEXITED 0 -> ()
+  | WEXITED 3 -> error fmt cmd "Signal ABRT"
+  | WEXITED -1073741819 (* 0xC0000005 *) -> error fmt cmd "Signal SEGV"
+  | WEXITED s -> error fmt cmd (Printf.sprintf "Exit %d" s)
+  (* Those last 2 cases are dead code on Windows *)
+  | WSIGNALED s ->
+      let msg =
+        match List.assoc_opt s signals with
+        | Some signal -> "Signal " ^ signal
+        | None -> Printf.sprintf "Unknown signal %d" s
+      in
+      error fmt cmd msg
+  | WSTOPPED s ->
+      let msg =
+        match List.assoc_opt s signals with
+        | Some signal -> "Stop with signal " ^ signal
+        | None -> Printf.sprintf "Stop with unknown signal %d" s
+      in
+      error fmt cmd msg);
+  status = WEXITED 0
+
+let pp_status = if Sys.win32 then pp_status_win else pp_status_unix
+let start_time = Unix.time ()
+
+let deadline =
+  let getfloat v = Option.bind (Sys.getenv_opt v) float_of_string_opt in
+  let global = Option.value ~default:Float.infinity (getfloat "DEADLINE") in
+  match getfloat "TEST_TIMEOUT" with
+  | None -> global
+  | Some t -> min global (start_time +. (t *. 60.))
+
+let deadline_watcher pid () =
+  let open Unix in
+  assert (deadline > start_time);
+  if Float.is_finite deadline then (
+    sleepf (deadline -. start_time);
+    Atomic.set timed_out true;
+    if not Sys.win32 then (
+      (* let's give it a little time to stop *)
+      kill pid Sys.sigterm;
+      sleep 2);
+    kill pid Sys.sigkill)
+
+let log_time cmd =
+  match Sys.getenv_opt "TIMELOGDIR" with
+  | None -> ()
+  | Some d ->
+      let f = Filename.concat d "times.log" in
+      let flags = [ Open_wronly; Open_append; Open_creat; Open_binary ] in
+      Out_channel.with_open_gen flags 0o666 f @@ fun oc ->
+      let dur = int_of_float (Unix.time () -. start_time) in
+      let hours = dur / 3600
+      and minutes = dur mod 3600 / 60
+      and seconds = dur mod 60 in
+      if hours > 0 then
+        Printf.fprintf oc "%-40s finished in %d:%02d:%02d (%ds)\n" cmd hours
+          minutes seconds dur
+      else
+        Printf.fprintf oc "%-40s finished in   %02d:%02d (%ds)\n" cmd minutes
+          seconds dur
+
+let run ofmt efmt argv =
+  let argv =
+    match argv with [| cmd |] -> [| cmd; "--verbose" |] | _ -> argv
+  in
+  let testdir = Filename.basename (Sys.getcwd ()) in
+  let exe, cmd =
+    if Filename.is_implicit argv.(0) then
+      ( Filename.concat Filename.current_dir_name argv.(0),
+        Filename.concat testdir argv.(0) )
+    else (argv.(0), argv.(0))
+  in
+  let cmdline = String.concat " " (Array.to_list argv) in
+  if start_time < deadline then (
+    Format.fprintf ofmt "\n\nStarting (in %s) %s:\n%!" testdir cmdline;
+    let pid = Unix.(create_process exe argv stdin stdout stderr) in
+    ignore @@ Domain.spawn (deadline_watcher pid);
+    let _, status = Unix.waitpid [] pid in
+    log_time cmd;
+    pp_status efmt cmd status)
+  else (
+    warning ofmt cmd "Deadline reached, skipping test";
+    true)
+
+let _ =
+  let open Format in
+  if Array.length Sys.argv < 2 then (
+    fprintf err_formatter
+      "\nError: %s expects the\n  command to run as argument\n%!" Sys.argv.(0);
+    exit 1);
+  let cmd = Array.sub Sys.argv 1 (Array.length Sys.argv - 1) in
+  let success = run std_formatter err_formatter cmd in
+  if not success then exit 1