From d8b0df5b47738ca72de38fed66a44eb472bbfab9 Mon Sep 17 00:00:00 2001
From: Ed Morley <501702+edmorley@users.noreply.github.com>
Date: Fri, 28 Feb 2025 12:39:07 +0000
Subject: [PATCH] Enable libcnb tracing

This enables `libcnb`'s `trace` feature, which means traces, spans, and
events are written to OpenTelemetry export files on disk in the ephemeral
build container, which can then be read by the Heroku build system or
when debugging locally with Pack (so long as a suitable `--volume` mount
has been configured).

See:
https://github.com/heroku/libcnb.rs/pull/723

Closes #387.
GUS-W-15148608.
---
 Cargo.lock                   | 439 ++++++++++++++++++++++++++++++++++-
 buildpacks/ruby/CHANGELOG.md |   4 +
 buildpacks/ruby/Cargo.toml   |   2 +-
 3 files changed, 443 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 14db6446..8873322b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,15 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
+
+[[package]]
+name = "addr2line"
+version = "0.24.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfbe277e56a376000877090da837660b4427aad530e3028d44e0bffe4f89a1c1"
+dependencies = [
+ "gimli",
+]
 
 [[package]]
 name = "adler2"
@@ -34,18 +43,50 @@ version = "1.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55cc3b69f167a1ef2e161439aa98aed94e6028e5f9a59be9a6ffb47aef1651f9"
 
+[[package]]
+name = "anyhow"
+version = "1.0.96"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b964d184e89d9b6b67dd2715bc8e74cf3107fb2b529990c90cf517326150bf4"
+
 [[package]]
 name = "arrayvec"
 version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
+[[package]]
+name = "async-trait"
+version = "0.1.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "644dd749086bf3771a2fbc5f256fdb982d53f011c7d5d560304eafeecebce79d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
 
+[[package]]
+name = "backtrace"
+version = "0.3.74"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d82cb332cdfaed17ae235a638438ac4d4839913cc2af585c3c6746e8f8bee1a"
+dependencies = [
+ "addr2line",
+ "cfg-if",
+ "libc",
+ "miniz_oxide",
+ "object",
+ "rustc-demangle",
+ "windows-targets",
+]
+
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -136,6 +177,12 @@ dependencies = [
  "fun_run",
 ]
 
+[[package]]
+name = "bumpalo"
+version = "3.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1628fb46dfa0b37568d12e5edd512553eccf6a22a78e8bde00bb4aed84d5bdbf"
+
 [[package]]
 name = "byte-unit"
 version = "5.1.6"
@@ -517,6 +564,70 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6d5a32815ae3f33302d95fdcb2ce17862f8c65363dcfd29360480ba1001fc9c"
 
+[[package]]
+name = "futures-channel"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dff15bf788c671c1934e366d07e30c1814a8ef514e1af724a602e8a2fbe1b10"
+dependencies = [
+ "futures-core",
+]
+
+[[package]]
+name = "futures-core"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05f29059c0c2090612e8d742178b0580d2dc940c837851ad723096f87af6663e"
+
+[[package]]
+name = "futures-executor"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e28d1d997f585e54aebc3f97d39e72338912123a67330d723fdbb564d646c9f"
+dependencies = [
+ "futures-core",
+ "futures-task",
+ "futures-util",
+]
+
+[[package]]
+name = "futures-macro"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "162ee34ebcb7c64a8abebc059ce0fee27c2262618d7b60ed8faf72fef13c3650"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+]
+
+[[package]]
+name = "futures-sink"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e575fab7d1e0dcb8d0c7bcf9a63ee213816ab51902e6d244a95819acacf1d4f7"
+
+[[package]]
+name = "futures-task"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f90f7dce0722e95104fcb095585910c0977252f286e354b5e3bd38902cd99988"
+
+[[package]]
+name = "futures-util"
+version = "0.3.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9fa08315bb612088cc391249efdc3bc77536f16c91f6cf495e6fbe85b20a4a81"
+dependencies = [
+ "futures-core",
+ "futures-macro",
+ "futures-sink",
+ "futures-task",
+ "pin-project-lite",
+ "pin-utils",
+ "slab",
+]
+
 [[package]]
 name = "generic-array"
 version = "0.14.7"
@@ -550,6 +661,12 @@ dependencies = [
  "windows-targets",
 ]
 
+[[package]]
+name = "gimli"
+version = "0.31.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
+
 [[package]]
 name = "glob"
 version = "0.3.2"
@@ -619,6 +736,46 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
+[[package]]
+name = "http"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f16ca2af56261c99fba8bac40a10251ce8188205a4c448fbb745a2e4daa76fea"
+dependencies = [
+ "bytes",
+ "fnv",
+ "itoa",
+]
+
+[[package]]
+name = "http-body"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1efedce1fb8e6913f23e0c92de8e62cd5b772a67e7b3946df930a62566c93184"
+dependencies = [
+ "bytes",
+ "http",
+]
+
+[[package]]
+name = "http-body-util"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "793429d76616a256bcb62c2a2ec2bed781c8307e797e2598c50010f2bee2544f"
+dependencies = [
+ "bytes",
+ "futures-util",
+ "http",
+ "http-body",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "icu_collections"
 version = "1.5.0"
@@ -814,6 +971,16 @@ version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d75a2a4b1b190afb6f5425f10f6a8f959d2ea0b9c2b1d79553551850539e4674"
 
+[[package]]
+name = "js-sys"
+version = "0.3.77"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1cfaf33c695fc6e08064efbc1f72ec937429614f25eef83af942d0e227c3a28f"
+dependencies = [
+ "once_cell",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.5.0"
@@ -832,10 +999,15 @@ version = "0.27.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bd4c8b7af2e8c24d9830f2f58c3fb95f8fdbf79eb723f9ee395bad6cde21a329"
 dependencies = [
+ "futures-core",
  "libcnb-common",
  "libcnb-data",
  "libcnb-proc-macros",
+ "opentelemetry",
+ "opentelemetry-proto",
+ "opentelemetry_sdk",
  "serde",
+ "serde_json",
  "thiserror",
  "toml",
 ]
@@ -1005,12 +1177,65 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "object"
+version = "0.36.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62948e14d923ea95ea2c7c86c71013138b66525b86bdc08d2dcc262bdb497b87"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.20.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "945462a4b81e43c4e3ba96bd7b49d834c6f61198356aa858733bc4acf3cbe62e"
 
+[[package]]
+name = "opentelemetry"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "236e667b670a5cdf90c258f5a55794ec5ac5027e960c224bff8367a59e1e6426"
+dependencies = [
+ "futures-core",
+ "futures-sink",
+ "js-sys",
+ "pin-project-lite",
+ "thiserror",
+ "tracing",
+]
+
+[[package]]
+name = "opentelemetry-proto"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56f8870d3024727e99212eb3bb1762ec16e255e3e6f58eeb3dc8db1aa226746d"
+dependencies = [
+ "base64",
+ "hex",
+ "opentelemetry",
+ "opentelemetry_sdk",
+ "prost",
+ "serde",
+ "tonic",
+]
+
+[[package]]
+name = "opentelemetry_sdk"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "84dfad6042089c7fc1f6118b7040dc2eb4ab520abbf410b79dc481032af39570"
+dependencies = [
+ "futures-channel",
+ "futures-executor",
+ "futures-util",
+ "opentelemetry",
+ "percent-encoding",
+ "rand 0.8.5",
+ "thiserror",
+]
+
 [[package]]
 name = "ordered-float"
 version = "3.9.2"
@@ -1036,6 +1261,38 @@ dependencies = [
  "indexmap",
 ]
 
+[[package]]
+name = "pin-project"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfe2e71e1471fe07709406bf725f710b02927c9c54b2b5b2ec0e8087d97c327d"
+dependencies = [
+ "pin-project-internal",
+]
+
+[[package]]
+name = "pin-project-internal"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6e859e6e5bd50440ab63c47e3ebabc90f26251f7c73c3d3e837b74a1cc3fa67"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+]
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b3cff922bd51709b605d9ead9aa71031d81447142d828eb4a6eba76fe619f9b"
+
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
 [[package]]
 name = "pkg-config"
 version = "0.3.31"
@@ -1079,6 +1336,29 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "prost"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2796faa41db3ec313a31f7624d9286acf277b52de526150b7e69f3debf891ee5"
+dependencies = [
+ "bytes",
+ "prost-derive",
+]
+
+[[package]]
+name = "prost-derive"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a56d757972c98b346a9b766e3f02746cde6dd1cd1d1d563472929fdd74bec4d"
+dependencies = [
+ "anyhow",
+ "itertools",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+]
+
 [[package]]
 name = "ptr_meta"
 version = "0.1.4"
@@ -1301,6 +1581,12 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "rustc-demangle"
+version = "0.1.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "719b953e2095829ee67db738b3bfa9fa368c94900df327b3f07fe6e794d2fe1f"
+
 [[package]]
 name = "rustix"
 version = "0.38.44"
@@ -1446,6 +1732,15 @@ version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
 
+[[package]]
+name = "slab"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f92a496fb766b417c996b9c5e57daf2f7ad3b0bebe1ccfca4856390e3d3bb67"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "smallvec"
 version = "1.14.0"
@@ -1600,6 +1895,27 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
 
+[[package]]
+name = "tokio"
+version = "1.43.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d61fa4ffa3de412bfea335c6ecff681de2b609ba3c77ef3e00e521813a9ed9e"
+dependencies = [
+ "backtrace",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "tokio-stream"
+version = "0.1.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eca58d7bba4a75707817a2c44174253f9236b2d5fbd055602e9d5c07c139a047"
+dependencies = [
+ "futures-core",
+ "pin-project-lite",
+ "tokio",
+]
+
 [[package]]
 name = "toml"
 version = "0.8.20"
@@ -1634,6 +1950,70 @@ dependencies = [
  "winnow",
 ]
 
+[[package]]
+name = "tonic"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877c5b330756d856ffcc4553ab34a5684481ade925ecc54bcd1bf02b1d0d4d52"
+dependencies = [
+ "async-trait",
+ "base64",
+ "bytes",
+ "http",
+ "http-body",
+ "http-body-util",
+ "percent-encoding",
+ "pin-project",
+ "prost",
+ "tokio-stream",
+ "tower-layer",
+ "tower-service",
+ "tracing",
+]
+
+[[package]]
+name = "tower-layer"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "121c2a6cda46980bb0fcd1647ffaf6cd3fc79a013de288782836f6df9c48780e"
+
+[[package]]
+name = "tower-service"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8df9b6e13f2d32c91b9bd719c00d1958837bc7dec474d94952798cc8e69eeec3"
+
+[[package]]
+name = "tracing"
+version = "0.1.41"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "784e0ac535deb450455cbfa28a6f0df145ea1bb7ae51b821cf5e7927fdcfbdd0"
+dependencies = [
+ "pin-project-lite",
+ "tracing-attributes",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-attributes"
+version = "0.1.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "395ae124c09f9e6918a2310af6038fba074bcf474ac352496d5910dd59a2226d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+]
+
+[[package]]
+name = "tracing-core"
+version = "0.1.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e672c95779cf947c5311f83787af4fa8fffd12fb27e4993211a84bdfd9610f9c"
+dependencies = [
+ "once_cell",
+]
+
 [[package]]
 name = "typenum"
 version = "1.18.0"
@@ -1749,6 +2129,63 @@ dependencies = [
  "wit-bindgen-rt",
 ]
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1edc8929d7499fc4e8f0be2262a241556cfc54a0bea223790e71446f2aab1ef5"
+dependencies = [
+ "cfg-if",
+ "once_cell",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2f0a0651a5c2bc21487bde11ee802ccaf4c51935d0d3d42a6101f98161700bc6"
+dependencies = [
+ "bumpalo",
+ "log",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fe63fc6d09ed3792bd0897b314f53de8e16568c2b3f7982f468c0bf9bd0b407"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ae87ea40c9f689fc23f209965b6fb8a99ad69aeeb0231408be24920604395de"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.98",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a05d73b933a847d6cccdda8f838a22ff101ad9bf93e33684f39c1f5f0eece3d"
+dependencies = [
+ "unicode-ident",
+]
+
 [[package]]
 name = "webpki-roots"
 version = "0.26.8"
diff --git a/buildpacks/ruby/CHANGELOG.md b/buildpacks/ruby/CHANGELOG.md
index a4ed999b..7bbb3d0d 100644
--- a/buildpacks/ruby/CHANGELOG.md
+++ b/buildpacks/ruby/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Enabled `libcnb`'s `trace` feature. ([#398](https://github.com/heroku/buildpacks-ruby/pull/398))
+
 ## [5.0.1] - 2025-01-13
 
 ### Fixed
diff --git a/buildpacks/ruby/Cargo.toml b/buildpacks/ruby/Cargo.toml
index eeaa485c..a582f521 100644
--- a/buildpacks/ruby/Cargo.toml
+++ b/buildpacks/ruby/Cargo.toml
@@ -18,7 +18,7 @@ glob = "0.3"
 indoc = "2"
 # libcnb has a much bigger impact on buildpack behaviour than any other dependencies,
 # so it's pinned to an exact version to isolate it from lockfile refreshes.
-libcnb = "=0.27.0"
+libcnb = { version = "=0.27.0", features = ["trace"] }
 libherokubuildpack = { version = "=0.27.0", default-features = false, features = ["digest"] }
 rand = "0.9"
 # TODO: Consolidate on either the regex crate or the fancy-regex crate, since this repo currently uses both.