better CI logs w/ gdb after core dump

.travis.yml

@@ -35,5 +35,17 @@ matrix:
 
 install:
   - pip install tox
+  - sudo apt-get install -y gdb  # install gdb
+
+
+before_script:
+  - ulimit -c unlimited -S       # enable core dumps
+
 
 script: tox -vv
+
+
+after_failure:
+  - pwd
+  - COREFILE=$(find . -maxdepth 1 -name "core*" | head -n 1) # find core file
+  - if [[ -f "$COREFILE" ]]; then EXECFILE=$(gdb -c "$COREFILE" -batch | grep "Core was generated" | tr -d "\`" | cut -d' ' -f5); file "$COREFILE"; gdb -c "$COREFILE" "$EXECFILE" -x continuous_integration/debug.gdb -batch; fi

continuous_integration/debug.gdb

@@ -0,0 +1,21 @@
+# commands to run on CI machine in event of testing core-dump
+
+set trace-commands on
+
+thread apply all bt
+
+f
+info args
+info locals
+
+up
+
+f
+info args
+info locals
+
+up
+
+f
+info args
+info locals