From 141f623669b2c9fb239f2d28933ba3da38736947 Mon Sep 17 00:00:00 2001
From: maurycy <5383+maurycy@users.noreply.github.com>
Date: Sat, 13 Jun 2026 03:14:04 +0200
Subject: [PATCH 1/3] sync chunks?

---
 Modules/_remote_debugging/frames.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Modules/_remote_debugging/frames.c b/Modules/_remote_debugging/frames.c
index d73cd080dc477f3..e7d2a2764390261 100644
--- a/Modules/_remote_debugging/frames.c
+++ b/Modules/_remote_debugging/frames.c
@@ -580,6 +580,14 @@ collect_frames_with_cache(
         return full_hit < 0 ? -1 : 0;
     }
 
+    assert(ctx->chunks != NULL);
+
+    if (ctx->chunks->count == 0) {
+        if (copy_stack_chunks(unwinder, ctx->thread_state_addr, ctx->chunks) < 0) {
+            PyErr_Clear();
+        }
+    }
+
     Py_ssize_t frames_before = PyList_GET_SIZE(ctx->frame_info);
 
     if (process_frame_chain(unwinder, ctx) < 0) {

From 8b7f97d86a3363c919afccda6bf4c8e14933f6cc Mon Sep 17 00:00:00 2001
From: maurycy <5383+maurycy@users.noreply.github.com>
Date: Sat, 13 Jun 2026 04:11:05 +0200
Subject: [PATCH 2/3] news

---
 .../Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst    | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst

diff --git a/Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst b/Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst
new file mode 100644
index 000000000000000..df8c73377ba76b9
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst
@@ -0,0 +1,4 @@
+Fix impossible stack traces (callers and callees cross called, orphans and
+incorrect lines) in the Tachyon profiler, by snapshotting the stack chunks
+before walking the frame chain on a cache miss. Patch by Maurycy
+Pawłowski-Wieroński.

From 39564f8adb5cd0145a9bd2417d2f2deb32643267 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maurycy=20Paw=C5=82owski-Wiero=C5=84ski?=
 <maurycy@maurycy.com>
Date: Sat, 13 Jun 2026 11:29:08 +0200
Subject: [PATCH 3/3] better news

---
 .../Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst  | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst b/Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst
index df8c73377ba76b9..428302e5f847f36 100644
--- a/Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst
+++ b/Misc/NEWS.d/next/Library/2026-06-13-04-11-00.gh-issue-151426.f2V67e.rst
@@ -1,4 +1,4 @@
 Fix impossible stack traces (callers and callees cross called, orphans and
-incorrect lines) in the Tachyon profiler, by snapshotting the stack chunks
-before walking the frame chain on a cache miss. Patch by Maurycy
-Pawłowski-Wieroński.
+incorrect lines) in the Tachyon profiler when caching frames, by snapshotting
+the stack chunks before walking the frame chain on a cache miss. Patch by
+Maurycy Pawłowski-Wieroński.