temp: backtrace memory-bio dtls12 segfault

Author: aidangarske

.github/workflows/diag.yml

@@ -60,20 +60,17 @@ jobs:
           grep -v 'would read block' /tmp/c.out | head -12
           exit $rc
 
-      - name: memory-bio-dtls -- is it DTLS1.3 specific?
+      - name: memory-bio-dtls -- backtrace the dtls1.2 segfault
         if: always()
         run: |
           cd dtls
           export LD_LIBRARY_PATH=/tmp/inst/lib
-          # A: as shipped -- picks DTLS 1.3 because the profile enables dtls13
-          gcc -g -o /tmp/mb13 memory-bio-dtls.c -I/tmp/inst/include \
-            -L/tmp/inst/lib -lwolfssl -lpthread -lm || exit 1
-          # B: same source, forced onto DTLS 1.2 by hiding WOLFSSL_DTLS13
           sed 's/#ifdef WOLFSSL_DTLS13/#if 0/' memory-bio-dtls.c > /tmp/mb12.c
-          gcc -g -o /tmp/mb12 /tmp/mb12.c -I/tmp/inst/include \
+          gcc -g -O0 -o /tmp/mb12 /tmp/mb12.c -I/tmp/inst/include \
             -L/tmp/inst/lib -lwolfssl -lpthread -lm || exit 1
-          for v in 13 12; do
-            timeout 10 /tmp/mb$v > /tmp/o$v.txt 2>&1
-            echo "=== DTLS 1.$v : rc=$? (0=works, 124=hangs)"
-            grep -iE 'success|Version:|Cipher|client msg' /tmp/o$v.txt | head -5
-          done
+          ulimit -c unlimited
+          echo "=== confirm the forced method:"
+          grep -n -A4 '#if 0' /tmp/mb12.c | head -8
+          echo "=== run under gdb:"
+          gdb -batch -ex run -ex 'thread apply all bt' --args /tmp/mb12 2>&1 \
+            | grep -vE '^\[|^Reading|^Downloading|^warning:' | tail -40