fuzz: document -D flag for faster development builds
What the developer wrote
Authored by Joost Jager
fuzz: document -D flag for faster development builds
What changed, and why it matters
This commit only adds documentation to the fuzz testing README explaining how to use an existing `-D` (development) build flag for faster fuzzing builds. It changes no code, build scripts, or security-sensitive behavior.
No security action needed. This is a documentation-only change.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The diff is a 13-line addition to fuzz/README.md documenting that cargo +nightly fuzz run ... -D <target> enables a faster development build mode. The flag itself is pre-existing; the commit merely documents it. No source code, configuration defaults, or cryptographic/logic paths are modified.
Changed components
fuzz/README.mdInspect captured patch +13 / −0
diff --git a/fuzz/README.md b/fuzz/README.md
index 4b6e0d1..cfdab49 100644
--- a/fuzz/README.md
+++ b/fuzz/README.md
@@ -68,6 +68,19 @@ cargo +nightly fuzz run --features "libfuzzer_fuzz" msg_ping_target
Note: If you encounter a `SIGKILL` during run/build check for OOM in kernel logs and consider
increasing RAM size for VM.
+##### Fast builds for development
+
+The default build uses LTO and single codegen unit, which is slow. For faster iteration during
+development, use the `-D` (dev) flag:
+
+```shell
+cargo +nightly fuzz run --features "libfuzzer_fuzz" -D msg_ping_target
+```
+
+The `-D` flag builds in development mode with faster compilation (still has optimizations via
+`opt-level = 1`). The first build will be slow as it rebuilds the standard library with
+sanitizer instrumentation, but subsequent builds will be fast.
+
If you wish to just generate fuzzing binary executables for `libFuzzer` and not run them:
```shell
cargo +nightly fuzz build --features "libfuzzer_fuzz" msg_ping_target
Why this scored 15/100
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