Add support for cargo --profile

Closes #167

Author: madadam

src/bin/cargo-flamegraph.rs

@@ -12,6 +12,10 @@ struct Opt {
     #[clap(long)]
     dev: bool,
 
+    /// Build with the specified profile
+    #[clap(long)]
+    profile: Option<String>,
+
     /// package with the binary to run
     #[clap(short, long)]
     package: Option<String>,
@@ -84,9 +88,13 @@ fn build(opt: &Opt, kind: impl IntoIterator<Item = String>) -> anyhow::Result<Ve
         cmd.arg("build");
     }
 
-    // do not use `--release` when we are building for `bench`
-    if !opt.dev && opt.bench.is_none() {
-        cmd.arg("--release");
+    if let Some(profile) = &opt.profile {
+        cmd.arg("--profile").arg(profile);
+    } else {
+        // do not use `--release` when we are building for `bench`
+        if !opt.dev && opt.bench.is_none() {
+            cmd.arg("--release");
+        }
     }
 
     if let Some(ref package) = opt.package {

src/lib.rs

@@ -501,7 +501,7 @@ pub struct FlamegraphOptions {
     pub notes: Option<String>,
 
     /// Omit functions smaller than <FLOAT> pixels
-    #[clap(long, default_value = "0.01f32", value_name = "FLOAT")]
+    #[clap(long, default_value = "0.01", value_name = "FLOAT")]
     pub min_width: f64,
 
     /// Image width in pixels