Disable lto and explicit profile

src/options.rs

@@ -50,14 +50,17 @@ pub enum BuildMode {
 
 #[derive(Clone, Debug, Eq, PartialEq, Parser)]
 pub struct BuildOptions {
-    #[arg(short = 'D', long, conflicts_with = "release")]
+    #[arg(short = 'D', long, conflicts_with_all = ["release", "profile"])]
     /// Build artifacts in development mode, without optimizations
     pub dev: bool,
 
-    #[arg(short = 'O', long, conflicts_with = "dev")]
+    #[arg(short = 'O', long, conflicts_with_all = ["dev", "profile"])]
     /// Build artifacts in release mode, with optimizations
     pub release: bool,
 
+    #[arg(long, conflicts_with_all = ["dev", "release"])]
+    pub profile: Option<String>,
+
     #[arg(short = 'a', long)]
     /// Build artifacts with debug assertions and overflow checks enabled (default if not -O)
     pub debug_assertions: bool,
@@ -167,6 +170,20 @@ pub struct BuildOptions {
     pub disable_branch_folding: Option<bool>,
 }
 
+impl BuildOptions {
+    pub fn profile_name(&self) -> &str {
+        // if no explicit profile is given then we default to release
+        // mode unless debug mode is explicitly requested.
+        if let Some(profile) = &self.profile {
+            profile
+        } else if !self.dev {
+            "release"
+        } else {
+            "dev"
+        }
+    }
+}
+
 impl stdfmt::Display for BuildOptions {
     fn fmt(&self, f: &mut stdfmt::Formatter) -> stdfmt::Result {
         if self.dev {
@@ -177,6 +194,10 @@ impl stdfmt::Display for BuildOptions {
             write!(f, " -O")?;
         }
 
+        if let Some(profile) = &self.profile {
+            write!(f, " --profile {profile}")?;
+        }
+
         if self.debug_assertions {
             write!(f, " -a")?;
         }
@@ -249,6 +270,7 @@ mod test {
         let default_opts = BuildOptions {
             dev: false,
             release: false,
+            profile: None,
             debug_assertions: false,
             verbose: false,
             no_default_features: false,
@@ -277,6 +299,10 @@ mod test {
                 release: true,
                 ..default_opts.clone()
             },
+            BuildOptions {
+                profile: Some("fuzz".to_string()),
+                ..default_opts.clone()
+            },
             BuildOptions {
                 debug_assertions: true,
                 ..default_opts.clone()

src/project.rs

@@ -140,10 +140,16 @@ impl FuzzProject {
             // --target=<TARGET> won't pass rustflags to build scripts
             .arg("--target")
             .arg(&build.triple);
-        // we default to release mode unless debug mode is explicitly requested
-        if !build.dev {
-            cmd.args(["--release", "--config", "profile.release.debug=true"]);
-        }
+        let profile = build.profile_name();
+
+        cmd.args([
+            &format!("--profile={profile}"),
+            "--config",
+            &format!("profile.{profile}.debug=true"),
+            "--config",
+            &format!("profile.{profile}.lto=false"),
+        ]);
+
         if build.verbose {
             cmd.arg("--verbose");
         }
@@ -740,10 +746,11 @@ impl FuzzProject {
         corpus_dir: &Path,
     ) -> Result<(Command, tempfile::TempDir)> {
         let bin_path = {
-            let profile_subdir = if coverage.build.dev {
-                "debug"
-            } else {
-                "release"
+            // See https://doc.rust-lang.org/cargo/guide/build-cache.html for the mapping.
+            let profile_subdir = match coverage.build.profile_name() {
+                "dev" | "test" => "debug",
+                "release" | "bench" => "release",
+                other => other,
             };
 
             let target_dir = self