Capture invalid announcement rejections in Phase 4

Update parse failures script to also extract 'Invalid announcement'
rejections from logs. These are announcement events that failed
validation (e.g., multiple clone tags instead of single tag with
multiple values).

Changes:
- Search for 'Event rejected by write policy' pattern with 'Invalid announcement'
- Search for 'Rejected repository announcement' pattern from builder
- Extract event_id, kind, and reason from rejection logs
- Combine with [PARSE_FAIL] entries in output
- Deduplicate entries by event_id
- Update header to clarify both patterns are captured
- Update migration guide to document this
- Fix SIGPIPE handling in purgatory script (minor)

This captures the ~446 unique announcements rejected for NIP-34 format
violations (multiple clone tags), which were previously unexplained
in the migration analysis.

3 files changed, 256 insertions, 68 deletions

diff --git a/docs/how-to/migrate-to-ngit-grasp.md b/docs/how-to/migrate-to-ngit-grasp.md
index 00af6c8..62cad87 100644
--- a/docs/how-to/migrate-to-ngit-grasp.md
+++ b/docs/how-to/migrate-to-ngit-grasp.md
@@ -122,7 +122,7 @@ ls /path/to/git/npub1*/  # Should show *.git directories
 
 ### Phase 4 Needs the Correct Service Name
 
-> **CRITICAL:** Phase 4 extracts structured logs (`[PARSE_FAIL]`, `[PURGATORY_EXPIRED]`) from journald. These logs **ONLY exist in ngit-grasp services**, NOT in ngit-relay services.
+> **CRITICAL:** Phase 4 extracts structured logs (`[PARSE_FAIL]`, `[PURGATORY_EXPIRED]`, `Invalid announcement` rejections) from journald. These logs **ONLY exist in ngit-grasp services**, NOT in ngit-relay services.
 
 If you specify an ngit-relay service (like `ngit-relay.service`), Phase 4 will find **zero logs** and produce empty results. This is a common mistake that wastes time and produces misleading analysis.
 
@@ -140,10 +140,10 @@ If you specify an ngit-relay service (like `ngit-relay.service`), Phase 4 will f
 systemctl list-units 'ngit-*' --all
 
 # Check which service has structured logging (should be ngit-grasp)
-journalctl -u ngit-grasp-*.service | grep -E '\[PARSE_FAIL\]|\[PURGATORY_EXPIRED\]' | head -5
+journalctl -u ngit-grasp-*.service | grep -E '\[PARSE_FAIL\]|\[PURGATORY_EXPIRED\]|Invalid announcement' | head -5
 
 # Verify ngit-relay does NOT have structured logging
-journalctl -u ngit-relay.service | grep -E '\[PARSE_FAIL\]|\[PURGATORY_EXPIRED\]' | head -5
+journalctl -u ngit-relay.service | grep -E '\[PARSE_FAIL\]|\[PURGATORY_EXPIRED\]|Invalid announcement' | head -5
 # ^ This should return nothing
 
 # Use the archive service name for Phase 4
@@ -448,7 +448,7 @@ The analysis will continue without log data.
 
 **Most common cause:** You're querying the wrong service (ngit-relay instead of ngit-grasp).
 
-Structured logging (`[PARSE_FAIL]`, `[PURGATORY_EXPIRED]`) **only exists in ngit-grasp services**. If you specify an ngit-relay service, Phase 4 will find zero logs.
+Structured logging (`[PARSE_FAIL]`, `[PURGATORY_EXPIRED]`, `Invalid announcement` rejections) **only exists in ngit-grasp services**. If you specify an ngit-relay service, Phase 4 will find zero logs.
 
 **How to diagnose:**
 
@@ -464,7 +464,7 @@ systemctl list-units 'ngit-grasp*' --all
 
 # 4. Verify the ngit-grasp service has structured logs
 journalctl -u ngit-grasp-relay-ngit-dev.service --since "7 days ago" | \
-  grep -E '\[PARSE_FAIL\]|\[PURGATORY_EXPIRED\]' | head -5
+  grep -E '\[PARSE_FAIL\]|\[PURGATORY_EXPIRED\]|Invalid announcement' | head -5
 ```
 
 **How to fix:**
@@ -482,12 +482,14 @@ journalctl -u ngit-grasp-relay-ngit-dev.service --since "7 days ago" | \
 
 1. **Structured logging not deployed:** If the ngit-grasp instance doesn't have the logging improvements deployed, no structured logs will exist. Check the ngit-grasp version.
 
-2. **No events in time window:** If there genuinely were no parse failures or purgatory expiry events, the files will be empty. This is valid - it means everything parsed successfully.
+2. **No events in time window:** If there genuinely were no parse failures, purgatory expiry events, or invalid announcement rejections, the files will be empty. This is valid - it means everything parsed successfully.
 
 3. **Wrong time range:** The default is 30 days. If your archive has been running longer, you may need `--since` to extend the range.
 
 **Prevention:** The migration scripts now validate the service name and will error if you specify an ngit-relay service.
 
+**Note on "Invalid announcement" rejections:** These are announcements (kind 30617) that were rejected by the write policy due to format violations. The most common reason is "multiple clone tags found" - the NIP-34 spec requires a single clone tag with multiple values, not multiple clone tags. These rejections are logged as `Event rejected by write policy ... reason=Invalid announcement: ...`.
+
 ### Event counts are multiples of 250
 
 This suggests pagination may have failed. The scripts use `--paginate` by default, but if you see exactly 250, 500, 750 events, verify the relay is responding correctly.
@@ -529,7 +531,11 @@ The analysis is split into 5 modular phases:
                               ↓
 ┌─────────────────────────────────────────────────────────────────┐
 │ PHASE 4: Log-Based Categories (VPS required)                    │
-│ Extracts [PARSE_FAIL] and [PURGATORY_EXPIRED] from logs         │
+│ Extracts structured logs from the archive service:              │
+│   - [PARSE_FAIL] - Events that failed to parse                  │
+│   - [PURGATORY_EXPIRED] - Repos where git data never arrived    │
+│   - "Invalid announcement" - Announcements rejected for format  │
+│     violations (e.g., multiple clone tags)                      │
 │ Provides context for why repos failed to sync                   │
 └─────────────────────────────────────────────────────────────────┘
                               ↓
diff --git a/docs/how-to/migration-scripts/30-extract-parse-failures.sh b/docs/how-to/migration-scripts/30-extract-parse-failures.sh
index d4f0ff2..114a44d 100755
--- a/docs/how-to/migration-scripts/30-extract-parse-failures.sh
+++ b/docs/how-to/migration-scripts/30-extract-parse-failures.sh
@@ -3,7 +3,8 @@
 # 30-extract-parse-failures.sh - Extract parse failure events from systemd logs
 #
 # PHASE 4a of the GRASP relay to ngit-grasp migration analysis pipeline.
-# Extracts structured [PARSE_FAIL] log entries from journalctl.
+# Extracts structured [PARSE_FAIL] log entries AND "Invalid announcement"
+# rejections from journalctl.
 #
 # USAGE:
 #   ./30-extract-parse-failures.sh <service-name> <output-dir> [options]
@@ -27,24 +28,34 @@
 #   <output-dir>/parse-failures.txt
 #
 # OUTPUT FORMAT (TSV):
-#   repo<TAB>npub<TAB>kind<TAB>event_id<TAB>reason
+#   event_id<TAB>kind<TAB>reason<TAB>repo<TAB>npub
 #
-# EXPECTED LOG FORMAT:
-#   The script looks for structured log entries in this format:
+# EXPECTED LOG FORMATS:
+#   The script looks for two types of log entries:
 #
-#   2026-01-22T10:30:45Z ngit-grasp[1234]: [PARSE_FAIL] kind=30618 event_id=abc123... reason="invalid refs format" repo=myrepo npub=npub1...
+#   1. Structured [PARSE_FAIL] entries:
+#      2026-01-22T10:30:45Z ngit-grasp[1234]: [PARSE_FAIL] kind=30618 event_id=abc123... reason="invalid refs format" repo=myrepo npub=npub1...
+#
+#   2. "Invalid announcement" rejections (write policy):
+#      Event rejected by write policy event_id=abc123... relay=wss://... kind=30617 reason=Invalid announcement: multiple clone tags found...
+#
+#   3. "Rejected repository announcement" (builder):
+#      Rejected repository announcement note1xxx: Invalid announcement: multiple clone tags found...
 #
 #   Required fields: kind, event_id, reason
-#   Optional fields: repo, npub (may not be available if parsing failed early)
+#   Optional fields: repo, npub (may not be available for all entry types)
 #
 # DEPENDENCY:
 #   This script requires logging improvements in ngit-grasp to emit structured
 #   [PARSE_FAIL] log entries. Until those are implemented, this script will
 #   find no matching entries (which is handled gracefully).
 #
+#   "Invalid announcement" rejections are logged by the write policy and
+#   should be present in any ngit-grasp deployment.
+#
 #   See: docs/how-to/migrate-to-ngit-grasp.md (Dependencies section)
 #
-#   Expected Rust logging code:
+#   Expected Rust logging code for [PARSE_FAIL]:
 #     tracing::warn!(
 #         target: "migration",
 #         "[PARSE_FAIL] kind={} event_id={} reason=\"{}\" repo={} npub={}",
@@ -53,7 +64,7 @@
 #
 # PREREQUISITES:
 #   - journalctl (systemd)
-#   - grep, awk (standard Unix tools)
+#   - grep, awk, sed (standard Unix tools)
 #   - Access to systemd journal (may require sudo or journal group membership)
 #
 # RUNTIME: Depends on log volume, typically < 30 seconds
@@ -121,15 +132,17 @@ usage() {
     echo "  $0 ngit-grasp.service output/logs --since '2026-01-01'"
     echo "  $0 ngit-grasp.service output/logs --since '2026-01-15' --until '2026-01-22'"
     echo ""
-    echo "Expected log format:"
+    echo "Expected log formats:"
     echo "  [PARSE_FAIL] kind=30618 event_id=abc123 reason=\"...\" repo=myrepo npub=npub1..."
+    echo "  Event rejected by write policy event_id=abc123 ... kind=30617 reason=Invalid announcement: ..."
+    echo "  Rejected repository announcement note1xxx: Invalid announcement: ..."
     exit 1
 }
 
-# Parse a single log line and extract fields
+# Parse a [PARSE_FAIL] log line and extract fields
 # Input: log line containing [PARSE_FAIL]
-# Output: TSV line: repo<TAB>npub<TAB>kind<TAB>event_id<TAB>reason
-parse_log_line() {
+# Output: TSV line: event_id<TAB>kind<TAB>reason<TAB>repo<TAB>npub
+parse_parse_fail_line() {
     local line="$1"
     
     # Extract fields using grep -oP (Perl regex) or awk
@@ -154,7 +167,56 @@ parse_log_line() {
     
     # Only output if we have the required fields
     if [[ -n "$kind" && -n "$event_id" && -n "$reason" ]]; then
-        printf '%s\t%s\t%s\t%s\t%s\n' "$repo" "$npub" "$kind" "$event_id" "$reason"
+        printf '%s\t%s\t%s\t%s\t%s\n' "$event_id" "$kind" "$reason" "$repo" "$npub"
+    fi
+}
+
+# Parse an "Invalid announcement" rejection log line from write policy
+# Input: log line containing "Event rejected by write policy" with "Invalid announcement"
+# Output: TSV line: event_id<TAB>kind<TAB>reason<TAB>repo<TAB>npub
+# Note: repo and npub are empty for these entries (not available in log format)
+parse_write_policy_rejection_line() {
+    local line="$1"
+    
+    local kind event_id reason
+    
+    # Extract event_id=VALUE (hex string)
+    event_id=$(echo "$line" | grep -oP 'event_id=\K[a-f0-9]+' || echo "")
+    
+    # Extract kind=VALUE
+    kind=$(echo "$line" | grep -oP 'kind=\K[0-9]+' || echo "")
+    
+    # Extract reason=VALUE (everything after "reason=")
+    # The reason is unquoted and goes to end of line
+    reason=$(echo "$line" | grep -oP 'reason=\K.*$' || echo "")
+    
+    # Only output if we have the required fields
+    if [[ -n "$kind" && -n "$event_id" && -n "$reason" ]]; then
+        # repo and npub are empty for invalid announcement entries
+        printf '%s\t%s\t%s\t\t\n' "$event_id" "$kind" "$reason"
+    fi
+}
+
+# Parse a "Rejected repository announcement" log line from builder
+# Input: log line containing "Rejected repository announcement <note_id>: Invalid announcement:"
+# Output: TSV line: event_id<TAB>kind<TAB>reason<TAB>repo<TAB>npub
+# Note: The note_id is bech32 encoded, we need to extract it
+parse_builder_rejection_line() {
+    local line="$1"
+    
+    local note_id reason
+    
+    # Extract note_id (note1...) from "Rejected repository announcement note1xxx:"
+    note_id=$(echo "$line" | grep -oP 'Rejected repository announcement \Knote1[a-z0-9]+' || echo "")
+    
+    # Extract reason (everything after the note_id and colon)
+    reason=$(echo "$line" | grep -oP 'Rejected repository announcement note1[a-z0-9]+: \K.*$' || echo "")
+    
+    # Only output if we have the required fields
+    # Kind is always 30617 for announcements
+    if [[ -n "$note_id" && -n "$reason" ]]; then
+        # Use note_id as event_id (bech32 format), kind=30617, repo and npub empty
+        printf '%s\t%s\t%s\t\t\n' "$note_id" "30617" "$reason"
     fi
 }
 
@@ -260,21 +322,27 @@ main() {
         journal_cmd="$journal_cmd --until '$until_date'"
     fi
     
-    log_info "Running: $journal_cmd | grep '\\[PARSE_FAIL\\]'"
+    log_info "Running: $journal_cmd | grep '[PARSE_FAIL]' or 'Invalid announcement'"
     
     if [[ "$dry_run" == true ]]; then
         log_info "[DRY RUN] Would extract to: $output_dir/parse-failures.txt"
         
         # Show sample of what would be extracted
         log_info "Checking for matching log entries..."
-        local sample_count
-        sample_count=$(eval "$journal_cmd" 2>/dev/null | grep -c '\[PARSE_FAIL\]' || echo "0")
-        sample_count="${sample_count//[^0-9]/}"  # Strip non-numeric characters
-        sample_count="${sample_count:-0}"
-        log_info "Found $sample_count matching log entries"
+        local parse_fail_count invalid_announcement_count
+        parse_fail_count=$(eval "$journal_cmd" 2>/dev/null | grep -c '\[PARSE_FAIL\]' || echo "0")
+        parse_fail_count="${parse_fail_count//[^0-9]/}"  # Strip non-numeric characters
+        parse_fail_count="${parse_fail_count:-0}"
+        
+        invalid_announcement_count=$(eval "$journal_cmd" 2>/dev/null | grep 'Event rejected by write policy' | grep -c 'Invalid announcement' || echo "0")
+        invalid_announcement_count="${invalid_announcement_count//[^0-9]/}"
+        invalid_announcement_count="${invalid_announcement_count:-0}"
         
-        if [[ "$sample_count" -eq 0 ]]; then
-            log_warn "No [PARSE_FAIL] entries found in logs."
+        log_info "Found $parse_fail_count [PARSE_FAIL] entries"
+        log_info "Found $invalid_announcement_count 'Invalid announcement' rejections"
+        
+        if [[ "$parse_fail_count" -eq 0 && "$invalid_announcement_count" -eq 0 ]]; then
+            log_warn "No matching entries found in logs."
             log_warn "This is expected if ngit-grasp logging improvements are not yet deployed."
             log_warn "See: docs/how-to/migrate-to-ngit-grasp.md (Dependencies section)"
         fi
@@ -289,69 +357,159 @@ main() {
     local temp_file
     temp_file=$(mktemp)
     
-    # Extract and parse log entries
+    # Extract and parse log entries using streaming (avoids loading all logs into memory)
     log_info "Extracting log entries..."
     
-    # Get raw log lines containing [PARSE_FAIL]
-    # Capture stderr separately to detect journalctl errors
-    local raw_lines journal_stderr journal_exit
-    local temp_stderr
+    # Create temp files for intermediate results
+    local temp_stderr temp_parse_fail temp_write_policy_rejection temp_builder_rejection
     temp_stderr=$(mktemp)
+    temp_parse_fail=$(mktemp)
+    temp_write_policy_rejection=$(mktemp)
+    temp_builder_rejection=$(mktemp)
     
-    raw_lines=$(eval "$journal_cmd" 2>"$temp_stderr" | grep '\[PARSE_FAIL\]' || true)
-    journal_exit=$?
-    journal_stderr=$(cat "$temp_stderr" 2>/dev/null || true)
-    rm -f "$temp_stderr"
+    # Extract [PARSE_FAIL] entries directly to temp file (streaming)
+    log_info "  Searching for [PARSE_FAIL] entries..."
+    eval "$journal_cmd" 2>"$temp_stderr" | grep '\[PARSE_FAIL\]' > "$temp_parse_fail" || true
     
-    # Report any journalctl errors (but don't fail - empty logs are valid)
+    local journal_stderr
+    journal_stderr=$(cat "$temp_stderr" 2>/dev/null || true)
     if [[ -n "$journal_stderr" ]]; then
         log_warn "journalctl reported: $journal_stderr"
     fi
     
-    if [[ -z "$raw_lines" ]]; then
-        log_warn "No [PARSE_FAIL] entries found in logs."
+    # Extract "Event rejected by write policy" with "Invalid announcement" (streaming)
+    log_info "  Searching for write policy rejections..."
+    eval "$journal_cmd" 2>/dev/null | grep 'Event rejected by write policy' | grep 'Invalid announcement' > "$temp_write_policy_rejection" || true
+    
+    # Extract "Rejected repository announcement" from builder (streaming)
+    log_info "  Searching for builder rejections..."
+    eval "$journal_cmd" 2>/dev/null | grep 'Rejected repository announcement' | grep 'Invalid announcement' > "$temp_builder_rejection" || true
+    
+    rm -f "$temp_stderr"
+    
+    # Check if we found anything
+    local parse_fail_line_count write_policy_line_count builder_line_count
+    parse_fail_line_count=$(wc -l < "$temp_parse_fail")
+    parse_fail_line_count="${parse_fail_line_count//[^0-9]/}"
+    write_policy_line_count=$(wc -l < "$temp_write_policy_rejection")
+    write_policy_line_count="${write_policy_line_count//[^0-9]/}"
+    builder_line_count=$(wc -l < "$temp_builder_rejection")
+    builder_line_count="${builder_line_count//[^0-9]/}"
+    
+    log_info "  Found $parse_fail_line_count [PARSE_FAIL] log lines"
+    log_info "  Found $write_policy_line_count write policy rejection log lines"
+    log_info "  Found $builder_line_count builder rejection log lines"
+    
+    local total_invalid_announcement_lines=$((write_policy_line_count + builder_line_count))
+    
+    if [[ "$parse_fail_line_count" -eq 0 && "$total_invalid_announcement_lines" -eq 0 ]]; then
+        log_warn "No matching entries found in logs."
         log_warn ""
         log_warn "This is expected if ngit-grasp logging improvements are not yet deployed."
-        log_warn "The structured log format required by this script:"
+        log_warn "The script looks for:"
         log_warn ""
-        log_warn "  [PARSE_FAIL] kind=30618 event_id=abc123 reason=\"...\" repo=myrepo npub=npub1..."
+        log_warn "  1. [PARSE_FAIL] kind=30618 event_id=abc123 reason=\"...\" repo=myrepo npub=npub1..."
+        log_warn "  2. Event rejected by write policy event_id=... kind=30617 reason=Invalid announcement: ..."
         log_warn ""
         log_warn "See: docs/how-to/migrate-to-ngit-grasp.md (Dependencies section)"
         log_warn ""
         
         # Create empty output file with header comment
         {
-            echo "# Parse failures extracted from $service"
+            echo "# Parse failures and invalid announcements extracted from $service"
             echo "# Time range: ${since_date:-beginning} to ${until_date:-now}"
             echo "# Extracted: $(date -Iseconds)"
-            echo "# Format: repo<TAB>npub<TAB>kind<TAB>event_id<TAB>reason"
             echo "#"
-            echo "# NOTE: No [PARSE_FAIL] entries found."
+            echo "# Includes:"
+            echo "#   - [PARSE_FAIL] structured log entries"
+            echo "#   - \"Invalid announcement\" rejections"
+            echo "#"
+            echo "# Format: event_id<TAB>kind<TAB>reason<TAB>repo<TAB>npub"
+            echo "# Note: repo and npub may be empty for some entries"
+            echo "#"
+            echo "# NOTE: No matching entries found."
             echo "# This is expected if ngit-grasp logging improvements are not yet deployed."
         } > "$output_file"
         
+        rm -f "$temp_parse_fail" "$temp_write_policy_rejection" "$temp_builder_rejection"
         log_info "Created empty output file: $output_file"
         exit 0
     fi
     
     # Write header
     {
-        echo "# Parse failures extracted from $service"
+        echo "# Parse failures and invalid announcements extracted from $service"
         echo "# Time range: ${since_date:-beginning} to ${until_date:-now}"
         echo "# Extracted: $(date -Iseconds)"
-        echo "# Format: repo<TAB>npub<TAB>kind<TAB>event_id<TAB>reason"
+        echo "#"
+        echo "# Includes:"
+        echo "#   - [PARSE_FAIL] structured log entries"
+        echo "#   - \"Invalid announcement\" rejections"
+        echo "#"
+        echo "# Format: event_id<TAB>kind<TAB>reason<TAB>repo<TAB>npub"
+        echo "# Note: repo and npub may be empty for some entries"
     } > "$output_file"
     
-    # Parse each line
-    local count=0
-    while IFS= read -r line; do
-        local parsed
-        parsed=$(parse_log_line "$line")
-        if [[ -n "$parsed" ]]; then
-            echo "$parsed" >> "$output_file"
-            ((count++))
-        fi
-    done <<< "$raw_lines"
+    # Parse [PARSE_FAIL] entries
+    log_info "  Parsing [PARSE_FAIL] entries..."
+    local parse_fail_count=0
+    if [[ "$parse_fail_line_count" -gt 0 ]]; then
+        while IFS= read -r line; do
+            local parsed
+            parsed=$(parse_parse_fail_line "$line")
+            if [[ -n "$parsed" ]]; then
+                echo "$parsed" >> "$output_file"
+                parse_fail_count=$((parse_fail_count + 1))
+            fi
+        done < "$temp_parse_fail"
+    fi
+    
+    # Parse write policy rejection entries
+    log_info "  Parsing write policy rejection entries..."
+    local write_policy_count=0
+    if [[ "$write_policy_line_count" -gt 0 ]]; then
+        while IFS= read -r line; do
+            local parsed
+            parsed=$(parse_write_policy_rejection_line "$line")
+            if [[ -n "$parsed" ]]; then
+                echo "$parsed" >> "$output_file"
+                write_policy_count=$((write_policy_count + 1))
+            fi
+        done < "$temp_write_policy_rejection"
+    fi
+    
+    # Parse builder rejection entries
+    log_info "  Parsing builder rejection entries..."
+    local builder_count=0
+    if [[ "$builder_line_count" -gt 0 ]]; then
+        while IFS= read -r line; do
+            local parsed
+            parsed=$(parse_builder_rejection_line "$line")
+            if [[ -n "$parsed" ]]; then
+                echo "$parsed" >> "$output_file"
+                builder_count=$((builder_count + 1))
+            fi
+        done < "$temp_builder_rejection"
+    fi
+    
+    local invalid_announcement_count=$((write_policy_count + builder_count))
+    
+    rm -f "$temp_parse_fail" "$temp_write_policy_rejection" "$temp_builder_rejection"
+    
+    # Deduplicate by event_id (first column) - keep first occurrence
+    log_info "  Deduplicating entries..."
+    local deduped_file
+    deduped_file=$(mktemp)
+    # Preserve header lines (starting with #) and deduplicate data lines
+    grep '^#' "$output_file" > "$deduped_file"
+    grep -v '^#' "$output_file" | sort -t$'\t' -k1,1 -u >> "$deduped_file"
+    mv "$deduped_file" "$output_file"
+    
+    # Count final entries (excluding header lines)
+    local count
+    count=$(grep -v '^#' "$output_file" | wc -l)
+    count="${count//[^0-9]/}"  # Strip whitespace
+    count="${count:-0}"
     
     rm -f "$temp_file"
     
@@ -360,26 +518,45 @@ main() {
     log_info "=== Extraction Summary ==="
     log_info "Service: $service"
     log_info "Time range: ${since_date:-beginning} to ${until_date:-now}"
-    log_success "Extracted $count parse failure entries"
+    log_success "Extracted $count total entries"
+    log_info "  - [PARSE_FAIL] entries: $parse_fail_count"
+    log_info "  - Invalid announcement rejections: $invalid_announcement_count"
     echo ""
     log_info "Output file: $output_file"
     
     if [[ $count -gt 0 ]]; then
         echo ""
         log_info "Sample entries (first 5):"
-        tail -n +5 "$output_file" | head -5 | while IFS=$'\t' read -r repo npub kind event_id reason; do
-            echo "  kind=$kind repo=$repo reason=\"$reason\""
-        done
+        # Use a subshell to avoid SIGPIPE issues with set -e
+        # New format: event_id<TAB>kind<TAB>reason<TAB>repo<TAB>npub
+        (grep -v '^#' "$output_file" | head -5 | while IFS=$'\t' read -r event_id kind reason repo npub; do
+            echo "  kind=$kind event_id=${event_id:0:16}... reason=\"${reason:0:60}...\""
+        done) || true
     fi
     
     # Breakdown by kind
     if [[ $count -gt 0 ]]; then
         echo ""
         log_info "Breakdown by event kind:"
-        tail -n +5 "$output_file" | awk -F'\t' '{print $3}' | sort | uniq -c | sort -rn | while read -r cnt kind; do
+        # Use a subshell to avoid SIGPIPE issues with set -e
+        # kind is now column 2
+        (grep -v '^#' "$output_file" | awk -F'\t' '{print $2}' | sort | uniq -c | sort -rn | while read -r cnt kind; do
             echo "  kind $kind: $cnt failures"
-        done
+        done) || true
+    fi
+    
+    # Breakdown by reason pattern (for invalid announcements)
+    if [[ $invalid_announcement_count -gt 0 ]]; then
+        echo ""
+        log_info "Breakdown by reason pattern:"
+        # Extract the main reason type (before the colon details)
+        (grep -v '^#' "$output_file" | awk -F'\t' '{print $3}' | sed 's/:.*//' | sort | uniq -c | sort -rn | head -10 | while read -r cnt reason; do
+            echo "  $reason: $cnt"
+        done) || true
     fi
+    
+    # Explicit success exit
+    exit 0
 }
 
 main "$@"
diff --git a/docs/how-to/migration-scripts/31-extract-purgatory-expiry.sh b/docs/how-to/migration-scripts/31-extract-purgatory-expiry.sh
index a603a1e..a0c8ad0 100755
--- a/docs/how-to/migration-scripts/31-extract-purgatory-expiry.sh
+++ b/docs/how-to/migration-scripts/31-extract-purgatory-expiry.sh
@@ -356,7 +356,7 @@ main() {
         parsed=$(parse_log_line "$line")
         if [[ -n "$parsed" ]]; then
             echo "$parsed" >> "$output_file"
-            ((count++))
+            count=$((count + 1))
         fi
     done <<< "$raw_lines"
     
@@ -374,9 +374,10 @@ main() {
     if [[ $count -gt 0 ]]; then
         echo ""
         log_info "Sample entries (first 5):"
-        tail -n +5 "$output_file" | head -5 | while IFS=$'\t' read -r repo npub timestamp reason; do
+        # Use a subshell to avoid SIGPIPE issues with set -e
+        (tail -n +5 "$output_file" | head -5 | while IFS=$'\t' read -r repo npub timestamp reason; do
             echo "  repo=$repo npub=${npub:0:20}... timestamp=$timestamp"
-        done
+        done) || true
     fi
     
     # Show unique repos affected
@@ -388,9 +389,10 @@ main() {
         
         echo ""
         log_info "Repositories with purgatory expiry:"
-        tail -n +5 "$output_file" | awk -F'\t' '{print $1}' | sort | uniq -c | sort -rn | head -10 | while read -r cnt repo; do
+        # Use a subshell to avoid SIGPIPE issues with set -e
+        (tail -n +5 "$output_file" | awk -F'\t' '{print $1}' | sort | uniq -c | sort -rn | head -10 | while read -r cnt repo; do
             echo "  $repo: $cnt expiry events"
-        done
+        done) || true
         
         local total_repos
         total_repos=$(tail -n +5 "$output_file" | awk -F'\t' '{print $1}' | sort -u | wc -l)
@@ -398,6 +400,9 @@ main() {
             echo "  ... and $((total_repos - 10)) more repositories"
         fi
     fi
+    
+    # Explicit success exit
+    exit 0
 }
 
 main "$@"