[docs] Tweak fuzzer doc
diff --git a/TESTING.md b/TESTING.md
index f99ba7c..4efc64c 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -24,6 +24,8 @@
### Run tests with asan
+**NOTE**: this sometimes yields harder to read results than the full fuzzer
+
```shell
# For nice symbols tell asan how to symoblize. Note that it doesn't like versioned copies like llvm-symbolizer-3.8
# export ASAN_SYMBOLIZER_PATH=path to version-less llvm-symbolizer
@@ -63,7 +65,11 @@
# push your changs to a branch on googlefonts/harfbuzz
# In a local copy of oss-fuzz, edit projects/harfbuzz/Dockerfile
# Change the git clone to pull your branch
+
+# Do this periodically
sudo python infra/helper.py build_image harfbuzz
+
+# Do these to update/run
sudo python infra/helper.py build_fuzzers --sanitizer address harfbuzz
sudo python infra/helper.py run_fuzzer harfbuzz hb-subset-fuzzer
```
