From ad6313686d227981e7f25adb9c3e1c94699c6fdc Mon Sep 17 00:00:00 2001
From: Rudi Grinberg <me@rgrinberg.com>
Date: Wed, 31 Dec 2025 17:43:15 +0000
Subject: [PATCH 1/2] dev

Signed-off-by: Rudi Grinberg <me@rgrinberg.com>

From edd21876b0e08fa1eb8d58a902dc53ce415af3b4 Mon Sep 17 00:00:00 2001
From: Rudi Grinberg <me@rgrinberg.com>
Date: Sat, 17 Jan 2026 22:38:56 +0000
Subject: [PATCH 2/2] feature: make action trace library public

Signed-off-by: Rudi Grinberg <me@rgrinberg.com>
---
 doc/changes/added/13348.md       |  4 ++++
 dune-project                     |  9 +++++++++
 opam/dune-action-trace.opam      | 32 ++++++++++++++++++++++++++++++++
 otherlibs/dune-action-trace/dune |  1 +
 4 files changed, 46 insertions(+)
 create mode 100644 doc/changes/added/13348.md
 create mode 100644 opam/dune-action-trace.opam

diff --git a/doc/changes/added/13348.md b/doc/changes/added/13348.md
new file mode 100644
index 00000000000..deffc13c822
--- /dev/null
+++ b/doc/changes/added/13348.md
@@ -0,0 +1,4 @@
+- Introduce the `dune-action-trace` library. This public library is to be used
+  by custom actions to emit trace events while executed as part of a dune
+  build. The trace events emitted through this library will be incorporated
+  into dune's own trace (#13348, @rgrinberg)
diff --git a/dune-project b/dune-project
index c0fe6b6b0a2..9430b32d706 100644
--- a/dune-project
+++ b/dune-project
@@ -255,3 +255,12 @@ understood by dune language."))
  (maintenance_intent none)
  (description "Misc. Collection of File System Operations"))
 
+(package
+ (name dune-action-trace)
+ (dir otherlibs/dune-action-trace)
+ (synopsis "Dune Action Traces")
+ (depends
+  csexp
+  (ocaml (>= 4.08)))
+ (maintenance_intent none)
+ (description "Produce trace events from dune actions"))
diff --git a/opam/dune-action-trace.opam b/opam/dune-action-trace.opam
new file mode 100644
index 00000000000..3c3445173ca
--- /dev/null
+++ b/opam/dune-action-trace.opam
@@ -0,0 +1,32 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "Dune Action Traces"
+description: "Produce trace events from dune actions"
+maintainer: ["Jane Street Group, LLC <opensource@janestreet.com>"]
+authors: ["Jane Street Group, LLC <opensource@janestreet.com>"]
+license: "MIT"
+homepage: "https://github.com/ocaml/dune"
+doc: "https://dune.readthedocs.io/"
+bug-reports: "https://github.com/ocaml/dune/issues"
+depends: [
+  "dune" {>= "3.22"}
+  "csexp"
+  "ocaml" {>= "4.08"}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/ocaml/dune.git"
+x-maintenance-intent: ["none"]
diff --git a/otherlibs/dune-action-trace/dune b/otherlibs/dune-action-trace/dune
index 6de11088b2a..6b9b811f53e 100644
--- a/otherlibs/dune-action-trace/dune
+++ b/otherlibs/dune-action-trace/dune
@@ -1,3 +1,4 @@
 (library
+ (public_name dune-action-trace)
  (name dune_action_trace)
  (libraries csexp))