feat!: ship one binary — bundle exec-harness and memtrack, drop the LD_PRELOAD hack

.cargo/config.toml

@@ -0,0 +1,29 @@
+# Nothing here is `force = true`, so a shell exporting `CFLAGS` or `CPATH` wins
+# and breaks the musl build.
+#
+# `libbpf-sys` vendors elfutils, whose `configure` looks for `argp`, `obstack`
+# and `fts`; musl has none of them, so it stops before libelf even though a
+# libelf-only build never calls them. Pre-seeding the cache skips the checks.
+# Only autoconf reads these names, so a gnu build is unaffected.
+# Upstream tracks this at https://github.com/libbpf/libbpf-sys/issues/153.
+[env]
+ac_cv_search_argp_parse = "none required"
+ac_cv_search__obstack_free = "none required"
+ac_cv_search_fts_close = "none required"
+
+# The `argp.h` stub. `CPATH` and not a `-I` in the flags below, because
+# `relative = true` only works on a bare path. It is therefore global to the
+# build, so the stub defers to the real header wherever one exists.
+CPATH = { value = "crates/memtrack/musl", relative = true }
+
+# Debian's musl-gcc runs with -nostdinc, so the kernel UAPI headers libbpf needs
+# have to be added back, last so they never shadow the toolchain's own. Scoped
+# per target: cc-rs looks up `CFLAGS_<target>` before `CFLAGS`, and libbpf-sys
+# builds zlib, elfutils and libbpf from `cc::Tool::cflags_env()`.
+CFLAGS_x86_64_unknown_linux_musl = "-idirafter /usr/include/x86_64-linux-gnu -idirafter /usr/include"
+CFLAGS_aarch64_unknown_linux_musl = "-idirafter /usr/include/aarch64-linux-gnu -idirafter /usr/include"
+
+# rustc links with `-nodefaultlibs`; libbpf's C code needs the outline-atomic
+# helpers from libgcc on aarch64.
+[target.aarch64-unknown-linux-musl]
+rustflags = ["-C", "link-arg=-lgcc"]

.github/workflows/ci.yml

@@ -28,6 +28,9 @@ jobs:
       - uses: ./.github/actions/install-rust
         with:
           components: rustfmt, clippy
+      # Building the runner builds memtrack's vendored libbpf-sys with it.
+      - uses: ./.github/actions/install-bpf-deps
+        if: matrix.os == 'ubuntu-latest'
       - uses: j178/prek-action@4e14d07f9231acabce116ccfca13b13dd9755ece # v3.0.0
         with:
           extra-args: --all-files
@@ -102,6 +105,7 @@ jobs:
       - uses: ./.github/actions/install-rust
         with:
           cache-key: ${{ matrix.os }}
+      - uses: ./.github/actions/install-bpf-deps
       - name: Run tests
         run: cargo run -- exec ${{ matrix.extra-args }} -m simulation,walltime,memory --warmup-time 0s --max-rounds 5 -- sleep 1
 
@@ -112,10 +116,6 @@ jobs:
         with:
           submodules: true
       - uses: ./.github/actions/install-rust
-      - name: Install exec-harness
-        run: |
-          cargo install --path crates/exec-harness --locked
-
       - name: Run tests
         env:
           # Profiling system commands (e.g. `ls`) with samply is not yet supported on MacOS
@@ -234,21 +234,22 @@ jobs:
       - uses: ./.github/actions/install-rust
       - uses: ./.github/actions/install-bpf-deps
 
-      - name: Install memtrack and codspeed-runner
-        run: |
-          cargo install --locked --path crates/memtrack
-          cargo install --locked --path .
+      - name: Install codspeed-runner
+        run: cargo install --locked --path .
 
-      - name: Verify installed binaries
+      - name: Verify the installed binary
         run: |
-          which codspeed codspeed-memtrack
+          which codspeed
           codspeed --version
-          codspeed-memtrack --version
 
-      # The benchmarked command is memtrack itself, which needs file capabilities
-      # to load its eBPF programs even though the runner measures walltime.
+      # The benchmarked command is memtrack, a subcommand of the runner binary,
+      # which needs file capabilities to load its eBPF programs even though the
+      # runner measures walltime. The capabilities land on a copy of the runner,
+      # which the benchmarks call as `codspeed-memtrack`.
       - name: Grant memtrack file capabilities
-        run: codspeed setup --mode memory
+        run: |
+          codspeed setup --mode memory
+          sudo ln -s "$(codspeed setup memtrack-path)" /usr/local/bin/codspeed-memtrack
 
       # The write benchmarks overwrite these files every round; creating them
       # inside a measured round would time one-off disk allocation.
@@ -266,6 +267,32 @@ jobs:
           runner-version: rev:${{ env.CODSPEED_REV }}
           skip-hash-check-warning: true
 
+  musl-build:
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - runner: ubuntu-latest
+            target: x86_64-unknown-linux-musl
+          - runner: ubuntu-24.04-arm
+            target: aarch64-unknown-linux-musl
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          submodules: true
+      - uses: ./.github/actions/install-rust
+        with:
+          cache-key: ${{ matrix.target }}
+      - uses: ./.github/actions/install-bpf-deps
+      - name: Install the musl toolchain
+        run: |
+          sudo apt-get install -y musl-tools linux-libc-dev
+          rustup target add "${{ matrix.target }}"
+
+      - name: Build
+        run: cargo build --bin codspeed --target "${{ matrix.target }}"
+
   check:
     runs-on: ubuntu-latest
     if: always()
@@ -277,6 +304,7 @@ jobs:
       - basic-run-test
       - macos-basic-run-test
       - bpf-tests
+      - musl-build
       - benchmarks
       - memtrack-benchmarks
     steps:

CONTRIBUTING.md

@@ -10,50 +10,21 @@ prek install
 
 ## Release Process
 
-This repository is a Cargo workspace containing multiple crates. The release process differs depending on which crate you're releasing.
+This repository is a Cargo workspace, but only the main runner is released. The other crates
+are linked into its binary.
 
 ### Workspace Structure
 
 - **`codspeed-runner`**: The main CLI binary (`codspeed`)
-- **`memtrack`**: Memory tracking binary (`codspeed-memtrack`)
-- **`exec-harness`**: Execution harness binary
+- **`memtrack`**: Memory tracker, reached as `codspeed memtrack`
+- **`exec-harness`**: Execution harness, reached as `codspeed exec-harness`
 - **`runner-shared`**: Shared library used by other crates
 
-### Releasing Support Crates (memtrack, exec-harness, runner-shared)
-
-For any crate other than the main runner:
-
-```bash
-cargo release -p <PACKAGE_NAME> --execute <VERSION_BUMP>
-```
-
-Where `<VERSION_BUMP>` is one of: `alpha`, `beta`, `patch`, `minor`, or `major`.
-
-**Examples:**
-
-```bash
-# Release a new patch version of memtrack
-cargo release -p memtrack --execute patch
-
-# Release a beta version of exec-harness
-cargo release -p exec-harness --execute beta
-```
-
-#### Post-Release: Update Version References
-
-After releasing `memtrack` or `exec-harness`, you **must** update the version references in the runner code:
-
-1. **For memtrack**: Update the `MEMTRACK_INSTALLER` pin record in `src/binary_pins.rs` (see [Pinned binary hashes](#pinned-binary-hashes) below).
-
-2. **For exec-harness**: Update the `EXEC_HARNESS_INSTALLER` pin record in `src/binary_pins.rs`.
-
-These constants are used by the runner to download and install the correct versions of the binaries from GitHub releases.
-
 ### Pinned binary hashes
 
 Every binary the runner downloads at install time is SHA-256-pinned. The pins live in two places:
 
-- **`src/binary_pins.rs`** — the patched valgrind `.deb`, the memtrack installer, the exec-harness installer, and the mongo-tracer installer. Each artifact keeps its version, URL template, and hash together in a pin record.
+- **`src/binary_pins.rs`** — the patched valgrind `.deb` and the mongo-tracer installer. Each artifact keeps its version, URL template, and hash together in a pin record.
 - **`src/executor/helpers/introspected_golang/go.sh`** — the go-runner installer published by [CodSpeedHQ/codspeed-go](https://github.com/CodSpeedHQ/codspeed-go), one `<version> <sha256>` row per release in the `GO_RUNNER_INSTALLER_SHA256S` table. `DEFAULT_GO_RUNNER_VERSION` (just below the table) selects the row used by default.
 
 When you bump a pinned version (or add a new go-runner row), update the matching pin record / table row with the new version and its SHA-256.
@@ -84,16 +55,12 @@ These tests also run in CI, but running them locally before opening the PR avoid
 
 ### Releasing the Main Runner
 
-The main runner (`codspeed-runner`) should be released after ensuring all dependency versions are correct.
+The main runner (`codspeed-runner`) is the only crate that is released.
 
 #### Pre-Release Check
 
-**Verify binary version references**: Check that version constants in the runner code match the released versions:
-
-- `MEMTRACK_VERSION` in `src/binary_pins.rs`
-- `EXEC_HARNESS_VERSION` in `src/binary_pins.rs`
-
-Also confirm the SHA-256 entries in the pin records in `src/binary_pins.rs` match the released artifacts.
+Confirm the SHA-256 entries in the pin records in `src/binary_pins.rs` match the released
+artifacts they point at.
 
 #### Release Command
 

Cargo.toml

@@ -84,7 +84,7 @@ bytes = "1"
 [target.'cfg(target_os = "linux")'.dependencies]
 procfs = "0.18"
 caps = "0.5"
-memtrack = { path = "crates/memtrack", default-features = false }
+memtrack = { path = "crates/memtrack" }
 ipc-channel = { workspace = true }
 
 [dev-dependencies]
@@ -148,3 +148,17 @@ targets = ["aarch64-apple-darwin", "aarch64-unknown-linux-musl", "x86_64-unknown
 binaries.aarch64-apple-darwin = ["codspeed"]
 binaries.aarch64-unknown-linux-musl = ["codspeed"]
 binaries.x86_64-unknown-linux-musl = ["codspeed"]
+
+# memtrack's vendored libbpf/elfutils build runs as part of this package.
+[package.metadata.dist.dependencies.apt]
+build-essential = "*"
+pkgconf = "*"
+zlib1g-dev = "*"
+libbpf-dev = "*"
+musl-tools = "*"
+linux-libc-dev = "*"
+
+# Required for the vendored feature
+autopoint = "*"
+bison = "*"
+flex = "*"

crates/exec-harness/Cargo.toml

@@ -28,5 +28,6 @@ rstest = { workspace = true }
 [build-dependencies]
 cc = "1"
 
+# Bundled in the runner binary, not released on its own.
 [package.metadata.dist]
-targets = ["aarch64-unknown-linux-gnu", "x86_64-unknown-linux-gnu"]
+dist = false