ci+docs: minor cleanups

Change-Id: I280fd84d89061e34ad4e2aaa00ce63ad21b03565
diff --git a/.jenkins b/.jenkins
index b368a74..bc1c847 100755
--- a/.jenkins
+++ b/.jenkins
@@ -2,7 +2,9 @@
 set -e
 source .jenkins.d/util.sh
 
+export CACHE_DIR=${CACHE_DIR:-/tmp}
 export WAF_JOBS=${WAF_JOBS:-1}
+[[ $JOB_NAME == *"code-coverage" ]] && export DISABLE_ASAN=yes
 
 nanos() {
     # Cannot use date(1) because macOS does not support %N format specifier