diff --git a/.github/workflows/dev-lead-retry.yml b/.github/workflows/dev-lead-retry.yml
index bbbc30788..ab19e0fca 100644
--- a/.github/workflows/dev-lead-retry.yml
+++ b/.github/workflows/dev-lead-retry.yml
@@ -67,9 +67,41 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 30
     steps:
+      # Run the sweep at the SAME release as the harness it dispatches to (#2050).
+      # The dispatched runs execute scripts/ at the channel dev-lead.yml pins via
+      # `agent_ref`; running the sweep from main let it send payload fields that
+      # channel could not read yet (#2017). Read the pin from the default branch
+      # and check scripts/ out at it. Never hard-code the major here.
+      # One pin covers the whole sweep: target repos whose dev-lead.yml pins an
+      # older channel than this repo can still see the skew (#2086).
+      - name: Fetch dev-lead caller stub
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          ref: ${{ github.event.repository.default_branch }}
+          path: .channel-pin
+          sparse-checkout: .github/workflows/dev-lead.yml
+          sparse-checkout-cone-mode: false
+          token: ${{ secrets.GH_PAT_DON_PETRY || secrets.GH_PAT_WORKFLOWS || secrets.GITHUB_TOKEN }}
+          persist-credentials: false
+
+      - name: Resolve pinned dev-lead channel
+        id: channel
+        env:
+          STUB_FILE: .channel-pin/.github/workflows/dev-lead.yml
+        run: |
+          set -euo pipefail
+          ref="$(sed -nE "s/^[[:space:]]*agent_ref:[[:space:]]*[\"']?([^\"'[:space:]#]*).*/\1/p" "$STUB_FILE" | head -n 1)"
+          if [[ ! "$ref" =~ ^dev-lead/v[0-9]+-(next|ring0|ring1|stable)$ ]]; then
+            echo "::error::dev-lead.yml agent_ref '${ref}' is empty or not a dev-lead channel tag (dev-lead/v<N>-next|ring0|ring1|stable)"
+            exit 1
+          fi
+          echo "Sweep runs scripts/ at pinned channel: ${ref}"
+          echo "agent_ref=${ref}" >>"$GITHUB_OUTPUT"
+
       - name: Checkout agent repo
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
+          ref: ${{ steps.channel.outputs.agent_ref }}
           token: ${{ secrets.GH_PAT_DON_PETRY || secrets.GH_PAT_WORKFLOWS || secrets.GITHUB_TOKEN }}
           persist-credentials: false
 
diff --git a/AGENTS.md b/AGENTS.md
index 8a8f65563..b519c45f9 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -945,6 +945,19 @@ even though every ref looks valid, because the stub is ahead of the channel it p
      pinned channel resolves to a commit that declares the input.
 
   Doing these out of order (forwarding first) is exactly the skew this rule prevents.
+- **Same order for a new `client_payload` field from a dispatching sweep (#2050).** A sweep
+  such as `scripts/dev-lead-retry.sh` sends `repository_dispatch` payloads to the harness at
+  the pinned channel. A new field the sweep sends follows the same order: **(1)** the harness
+  change that reads the field (e.g. `scripts/dev-lead-intent.sh`) merges and **reaches the
+  pinned channel first**; **(2)** only then does the sweep change that sends it merge. Before
+  the backstop below, the sweep ran from `main`, so a sweep change that merged ahead of the
+  channel broke every dispatched run until the channel caught up (#2017: every
+  fix-bot-comment retry failed against `v139-stable`), and the canary gate charged those
+  failures to the next candidate. As a structural backstop, `dev-lead-retry.yml` now checks
+  out `scripts/` at the channel `dev-lead.yml` pins (`agent_ref`), not `main`, so the sweep
+  and the harness it dispatches to in this repo are the same release
+  (`tests/dev-lead/unit/test_dev_lead_retry_channel.bats`). The order still matters for
+  target repos that pin an older channel than this one (#2086).
 - **Enforcement.** The dev-lead prompt guardrail (part C, #1254) stops the agent from introducing the
   skew at the source; the **Part A CI guard (#1253)** is the belt-and-braces check that fails a PR whose
   caller-stub `with:` forwards an input the pinned channel does not declare.
diff --git a/tests/dev-lead/unit/test_dev_lead_retry_channel.bats b/tests/dev-lead/unit/test_dev_lead_retry_channel.bats
new file mode 100644
index 000000000..89016a7e6
--- /dev/null
+++ b/tests/dev-lead/unit/test_dev_lead_retry_channel.bats
@@ -0,0 +1,124 @@
+#!/usr/bin/env bats
+# Channel-skew guard for the dev-lead retry sweep (#2050).
+#
+# dev-lead-retry.yml runs scripts/dev-lead-retry.sh, which dispatches runs that
+# execute the harness at the channel this repo's caller stub pins
+# (dev-lead.yml `agent_ref`). Running the sweep from `main` let it send payload
+# fields the pinned harness could not read (#2017: every fix-bot-comment retry
+# failed until stable caught up). The sweep must therefore check out scripts/ at
+# that same channel. These tests pin:
+#   • the workflow reads `agent_ref` from dev-lead.yml on the default branch;
+#   • the agent checkout's `ref:` is that resolved value (never main, never a
+#     hard-coded major);
+#   • the resolve step (executed from the workflow text) accepts the live stub
+#     and other majors, and fails on an empty or malformed value.
+#
+# Run: bats tests/dev-lead/unit/test_dev_lead_retry_channel.bats
+
+bats_require_minimum_version 1.5.0
+
+REPO_ROOT="$(cd "$(dirname "$BATS_TEST_FILENAME")/../../.." && pwd)"
+WF="$REPO_ROOT/.github/workflows/dev-lead-retry.yml"
+STUB="$REPO_ROOT/.github/workflows/dev-lead.yml"
+
+setup() {
+  export GITHUB_OUTPUT="$BATS_TEST_TMPDIR/github_output"
+  : >"$GITHUB_OUTPUT"
+  RESOLVE_SCRIPT="$BATS_TEST_TMPDIR/resolve.sh"
+  # yq extracts the resolve step: skip locally without it, but never silently in CI.
+  if ! command -v yq >/dev/null 2>&1; then
+    if [ -n "${CI:-}" ]; then
+      echo "yq is required in CI" >&2
+      return 1
+    fi
+    skip "yq not installed"
+  fi
+  yq -r '.jobs.retry.steps[] | select(.id == "channel") | .run' "$WF" >"$RESOLVE_SCRIPT"
+}
+
+# Write a minimal caller stub fixture pinning agent_ref to $1.
+_stub_fixture() {
+  local f="$BATS_TEST_TMPDIR/dev-lead.yml"
+  cat >"$f" <<EOF
+jobs:
+  dev-lead:
+    uses: petry-projects/.github-private/.github/workflows/dev-lead-reusable.yml@$1
+    with:
+      agent_ref: $1
+EOF
+  printf '%s' "$f"
+}
+
+@test "workflow sparse-checks-out dev-lead.yml from the default branch first" {
+  local first
+  first="$(yq -r '.jobs.retry.steps[0].with["sparse-checkout"]' "$WF")"
+  [[ "$first" == *".github/workflows/dev-lead.yml"* ]]
+  [ "$(yq -r '.jobs.retry.steps[0].with.ref' "$WF")" = '${{ github.event.repository.default_branch }}' ]
+}
+
+@test "resolve step reads the stub file the first checkout fetched" {
+  local path stub_file
+  path="$(yq -r '.jobs.retry.steps[0].with.path' "$WF")"
+  stub_file="$(yq -r '.jobs.retry.steps[] | select(.id == "channel") | .env.STUB_FILE' "$WF")"
+  [ "$stub_file" = "$path/.github/workflows/dev-lead.yml" ]
+}
+
+@test "agent checkout ref is the resolved agent_ref channel" {
+  run yq -r '.jobs.retry.steps[] | select(.name == "Checkout agent repo") | .with.ref' "$WF"
+  [ "$status" -eq 0 ]
+  [ "$output" = '${{ steps.channel.outputs.agent_ref }}' ]
+}
+
+@test "channel is resolved before the agent checkout and before the sweep runs" {
+  local names
+  names="$(yq -r '.jobs.retry.steps[].name' "$WF")"
+  local resolve checkout sweep
+  resolve="$(grep -n 'Resolve pinned dev-lead channel' <<<"$names" | cut -d: -f1)"
+  checkout="$(grep -n '^Checkout agent repo$' <<<"$names" | cut -d: -f1)"
+  sweep="$(grep -n 'Scan and retry' <<<"$names" | cut -d: -f1)"
+  [ -n "$resolve" ] && [ -n "$checkout" ] && [ -n "$sweep" ]
+  [ "$resolve" -lt "$checkout" ]
+  [ "$checkout" -lt "$sweep" ]
+}
+
+@test "workflow does not hard-code a dev-lead major version" {
+  run grep -nE 'dev-lead/v[0-9]+' "$WF"
+  [ "$status" -eq 1 ]
+}
+
+@test "resolve step returns the live stub's agent_ref" {
+  local expected
+  expected="$(yq -r '.jobs["dev-lead"].with.agent_ref' "$STUB")"
+  [ -n "$expected" ] && [ "$expected" != "null" ]
+  STUB_FILE="$STUB" run bash "$RESOLVE_SCRIPT"
+  [ "$status" -eq 0 ]
+  grep -qxF "agent_ref=$expected" "$GITHUB_OUTPUT"
+}
+
+@test "resolve step accepts any major and every ring" {
+  local ch
+  for ch in dev-lead/v140-next dev-lead/v7-ring0 dev-lead/v12-ring1 dev-lead/v1000-stable; do
+    : >"$GITHUB_OUTPUT"
+    STUB_FILE="$(_stub_fixture "$ch")" run bash "$RESOLVE_SCRIPT"
+    [ "$status" -eq 0 ]
+    grep -qxF "agent_ref=$ch" "$GITHUB_OUTPUT"
+  done
+}
+
+@test "resolve step fails when agent_ref is missing" {
+  local f="$BATS_TEST_TMPDIR/dev-lead.yml"
+  printf 'jobs:\n  dev-lead:\n    uses: x\n' >"$f"
+  STUB_FILE="$f" run bash "$RESOLVE_SCRIPT"
+  [ "$status" -eq 1 ]
+  [ ! -s "$GITHUB_OUTPUT" ]
+}
+
+@test "resolve step fails on a malformed or non-channel agent_ref" {
+  local bad
+  for bad in main dev-lead/v139 dev-lead/vX-stable dev-lead/v139-canary pr-review/v1-stable 'dev-lead/v139-stable;x'; do
+    : >"$GITHUB_OUTPUT"
+    STUB_FILE="$(_stub_fixture "$bad")" run bash "$RESOLVE_SCRIPT"
+    [ "$status" -eq 1 ]
+    [ ! -s "$GITHUB_OUTPUT" ]
+  done
+}