From ccb38113eaaa4a13eb6aabe09520e49cc8519b84 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Burzy=C5=84ski?= <mateuszburzynski@gmail.com>
Date: Tue, 23 Jun 2026 12:00:39 +0200
Subject: [PATCH] Fix the computed publish plan path passed internally to
 `changeset pack` by the `/pack` subaction (#663)

* Fix the computed publish plan path passed internally to `changeset pack` by the `/pack` subaction

* fix it
---
 .changeset/all-cars-grin.md | 5 +++++
 src/select-mode/index.ts    | 4 +++-
 2 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/all-cars-grin.md

diff --git a/.changeset/all-cars-grin.md b/.changeset/all-cars-grin.md
new file mode 100644
index 0000000..17af9a3
--- /dev/null
+++ b/.changeset/all-cars-grin.md
@@ -0,0 +1,5 @@
+---
+"@changesets/action": patch
+---
+
+Fix the computed publish plan path passed internally to `changeset pack` by the `/pack` subaction.
diff --git a/src/select-mode/index.ts b/src/select-mode/index.ts
index 3fb1bc3..00e191d 100644
--- a/src/select-mode/index.ts
+++ b/src/select-mode/index.ts
@@ -64,7 +64,9 @@ async function getMode(): Promise<ModeResult> {
   const cwd = process.cwd();
   const publishPlanPath = path.join(
     process.env.RUNNER_TEMP ?? (await fs.realpath(os.tmpdir())),
-    `changeset-publish-plan-${Date.now()}.json`,
+    `changeset-publish-plan-${Date.now()}`,
+    // we need a stable filename here (in a unique dirname) so the artifact download can find this cleanly
+    "publish-plan.json",
   );
   await execChangesetsCli(["publish-plan", "--output", publishPlanPath], {
     cwd,