Automatically add --no-rosegment flag

.github/workflows/ci.yml

@@ -23,8 +23,10 @@ jobs:
       with:
         toolchain: stable
         components: rustfmt, clippy
+    - run: rustup toolchain install nightly # we need nightly for some tests which try to detect rustflags
     - run: cargo clippy --all-targets --all-features -- -D warnings
     - run: cargo fmt -- --check
+    - run: cargo test
 
   msrv:
     runs-on: ubuntu-latest

Cargo.toml

@@ -29,8 +29,12 @@ opener = "0.8.1"
 shlex = "2.0.1"
 rustc-demangle = { version = "0.1", features = ["std"] }
 
+[dev-dependencies]
+current_platform = "0.2"
+
 [target.'cfg(unix)'.dependencies]
 signal-hook = "0.4.1"
+serde_json = "1"
 
 [target.'cfg(windows)'.dependencies]
 blondie = "0.5.2"

README.md

@@ -39,7 +39,9 @@ your cargo binary directory. On most systems this is something like `~/.cargo/bi
 
 ## Linux
 
-**Note**: If you're using lld (which is the default since Rust 1.90.0) or mold on Linux, you must use the `--no-rosegment` flag. Otherwise perf will not be able to generate accurate stack traces ([explanation](https://crbug.com/919499#c16)).
+**Note**: If you're using lld (which is the default since Rust 1.90.0) or mold on Linux, you may need to use the `--no-rosegment` flag. Otherwise perf will not be able to generate accurate stack traces ([explanation](https://crbug.com/919499#c16)). `cargo-flamegraph` tries to add this flag automatically but your setup may require extra configuration.
+
+<details>
 
 For example, Rust 1.90.0 and later:
 
@@ -64,6 +66,8 @@ linker = "clang"
 rustflags = ["-Clink-arg=-fuse-ld=/usr/local/bin/mold", "-Clink-arg=-Wl,--no-rosegment"]
 ```
 
+</details>
+
 #### Debian (x86 and aarch)
 
 **Note**: Debian bullseye packages an outdated version of Rust which does not meet flamegraph's requirements. You should use [rustup](https://rustup.rs/) to install an up-to-date version of Rust, or upgrade to Debian bookworm or newer.