Fix reported memory errors in asan environment by using the debugging versions of python

Author: rhpvorderman

tox.ini

@@ -23,10 +23,12 @@ commands =
     coverage xml -i
 
 [testenv:asan]
+# Use debug python as default python gives address sanitization errors.
+basepython=python3d
 setenv=
     PYTHONDEVMODE=1
     PYTHONMALLOC=malloc
-    CFLAGS=-lasan -fsanitize=address -fno-omit-frame-pointer
+    CFLAGS=-lasan -fsanitize=address -fno-omit-frame-pointer -Og -g
 allowlist_externals=bash
 commands=
     bash -c 'export LD_PRELOAD=$(gcc -print-file-name=libasan.so) && printenv LD_PRELOAD && python -c "from isal import isal_zlib" && pytest tests'