From 55cf560626f3c186fc5260d36f6a0a23f7a672b3 Mon Sep 17 00:00:00 2001
From: Luke Carr <me+oss@carr.sh>
Date: Thu, 20 Nov 2025 12:58:27 +0000
Subject: [PATCH 1/7] Bump dependencies to latest versions

Bumps dependencies in `Cargo.toml` files, including fixes for breaking changes in upgrading `rand` crate from `0.8` to `0.9`, and bumped actions in GHA workflow files.
---
 .github/workflows/main.yml      | 10 +++++-----
 .github/workflows/pr_review.yml |  2 +-
 example-service/Cargo.toml      | 14 +++++++-------
 example-service/src/server.rs   |  6 +++---
 tarpc/Cargo.toml                | 28 ++++++++++++++--------------
 tarpc/src/context.rs            |  2 +-
 tarpc/src/trace.rs              |  6 +++---
 7 files changed, 34 insertions(+), 34 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 50d51a72e..4b506ecfd 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -42,7 +42,7 @@ jobs:
           - unix: "--features unix"
             serde-transport: ""
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
       - run: >
           cargo test --manifest-path tarpc/Cargo.toml
@@ -56,7 +56,7 @@ jobs:
     outputs:
       examples: ${{ steps.matrix.outputs.examples }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
       - id: matrix
         run: |
@@ -79,7 +79,7 @@ jobs:
       matrix:
         example: ${{ fromJSON(needs.list-examples.outputs.examples) }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
       - run: |
           cargo run --example "${{ matrix.example }}"
@@ -88,7 +88,7 @@ jobs:
     name: Rustfmt
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: rustfmt
@@ -98,7 +98,7 @@ jobs:
     name: Clippy
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
diff --git a/.github/workflows/pr_review.yml b/.github/workflows/pr_review.yml
index 597437883..16397be5e 100644
--- a/.github/workflows/pr_review.yml
+++ b/.github/workflows/pr_review.yml
@@ -4,7 +4,7 @@ jobs:
   clippy:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - uses: dtolnay/rust-toolchain@stable
       with:
         components: clippy
diff --git a/example-service/Cargo.toml b/example-service/Cargo.toml
index 3856b2f9c..0e7e33fc6 100644
--- a/example-service/Cargo.toml
+++ b/example-service/Cargo.toml
@@ -15,19 +15,19 @@ description = "An example server built on tarpc."
 
 [dependencies]
 anyhow = "1.0"
-clap = { version = "4.4.18", features = ["derive"] }
+clap = { version = "4.5.53", features = ["derive"] }
 log = "0.4"
 futures = "0.3"
-opentelemetry = { version = "0.30.0" }
-opentelemetry-otlp = { version = "0.30.0", features = ["grpc-tonic"] }
-rand = "0.8"
+opentelemetry = { version = "0.31.0" }
+opentelemetry-otlp = { version = "0.31.0", features = ["grpc-tonic"] }
+rand = "0.9"
 tarpc = { version = "0.37", path = "../tarpc", features = ["full"] }
 tokio = { version = "1", features = ["macros", "net", "rt-multi-thread"] }
 tracing = { version = "0.1" }
-tracing-opentelemetry = "0.31.0"
+tracing-opentelemetry = "0.32.0"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-opentelemetry_sdk = { version = "0.30.0", features = ["rt-tokio"] }
-opentelemetry-semantic-conventions = "0.30.0"
+opentelemetry_sdk = { version = "0.31.0", features = ["rt-tokio"] }
+opentelemetry-semantic-conventions = "0.31.0"
 
 [lib]
 name = "service"
diff --git a/example-service/src/server.rs b/example-service/src/server.rs
index 896280c3d..67836e069 100644
--- a/example-service/src/server.rs
+++ b/example-service/src/server.rs
@@ -7,8 +7,8 @@
 use clap::Parser;
 use futures::{future, prelude::*};
 use rand::{
-    distributions::{Distribution, Uniform},
-    thread_rng,
+    distr::{Distribution, Uniform},
+    rng,
 };
 use service::{World, init_tracing};
 use std::{
@@ -37,7 +37,7 @@ struct HelloServer(SocketAddr);
 impl World for HelloServer {
     async fn hello(self, _: context::Context, name: String) -> String {
         let sleep_time =
-            Duration::from_millis(Uniform::new_inclusive(1, 10).sample(&mut thread_rng()));
+            Duration::from_millis(Uniform::new_inclusive(1, 10).unwrap().sample(&mut rng()));
         time::sleep(sleep_time).await;
         format!("Hello, {name}! You are connected from {}", self.0)
     }
diff --git a/tarpc/Cargo.toml b/tarpc/Cargo.toml
index 778eb0938..e4de5518e 100644
--- a/tarpc/Cargo.toml
+++ b/tarpc/Cargo.toml
@@ -44,42 +44,42 @@ travis-ci = { repository = "google/tarpc" }
 anyhow = "1.0"
 fnv = "1.0"
 futures = "0.3"
-humantime = "2.0"
-pin-project = "1.0"
-rand = "0.8"
+humantime = "2.3"
+pin-project = "1.1"
+rand = "0.9"
 serde = { optional = true, version = "1.0", features = ["derive"] }
 static_assertions = "1.1.0"
 tarpc-plugins = { path = "../plugins", version = "0.14" }
 thiserror = "2.0"
 tokio = { version = "1", features = ["time"] }
-tokio-util = { version = "0.7.3", features = ["time"] }
+tokio-util = { version = "0.7.17", features = ["time"] }
 tokio-serde = { optional = true, version = "0.9" }
 tracing = { version = "0.1", default-features = false, features = [
     "attributes",
     "log",
 ] }
-tracing-opentelemetry = { version = "0.31.0", default-features = false }
-opentelemetry = { version = "0.30.0", default-features = false }
-opentelemetry-semantic-conventions = "0.30.0"
+tracing-opentelemetry = { version = "0.32.0", default-features = false }
+opentelemetry = { version = "0.31.0", default-features = false }
+opentelemetry-semantic-conventions = "0.31.0"
 
 [dev-dependencies]
-assert_matches = "1.4"
+assert_matches = "1.5"
 bincode = { version = "2.0", features = ["serde"] }
 bytes = { version = "1", features = ["serde"] }
-flate2 = "1.0"
+flate2 = "1.1"
 futures-test = "0.3"
-opentelemetry = { version = "0.30.0", default-features = false }
-opentelemetry-otlp = { version = "0.30.0", features = ["grpc-tonic"] }
-opentelemetry_sdk = { version = "0.30.0", features = ["rt-tokio"] }
+opentelemetry = { version = "0.31.0", default-features = false }
+opentelemetry-otlp = { version = "0.31.0", features = ["grpc-tonic"] }
+opentelemetry_sdk = { version = "0.31.0", features = ["rt-tokio"] }
 pin-utils = "0.1.0"
 serde_bytes = "0.11"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tokio = { version = "1", features = ["full", "test-util", "tracing"] }
-console-subscriber = "0.4"
+console-subscriber = "0.5"
 tokio-serde = { version = "0.9", features = ["json", "bincode"] }
 trybuild = "1.0"
 tokio-rustls = "0.26"
-rustls-pemfile = "2.0"
+rustls-pemfile = "2.2"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/tarpc/src/context.rs b/tarpc/src/context.rs
index 8e77cf223..f2a11bbab 100644
--- a/tarpc/src/context.rs
+++ b/tarpc/src/context.rs
@@ -142,7 +142,7 @@ pub(crate) trait SpanExt {
 
 impl SpanExt for tracing::Span {
     fn set_context(&self, context: &Context) {
-        self.set_parent(
+        let _ = self.set_parent(
             opentelemetry::Context::new()
                 .with_remote_span_context(opentelemetry::trace::SpanContext::new(
                     opentelemetry::trace::TraceId::from(context.trace_context.trace_id),
diff --git a/tarpc/src/trace.rs b/tarpc/src/trace.rs
index d172dc2e2..3e4fcf296 100644
--- a/tarpc/src/trace.rs
+++ b/tarpc/src/trace.rs
@@ -81,7 +81,7 @@ impl Context {
     pub(crate) fn new_child(&self) -> Self {
         Self {
             trace_id: self.trace_id,
-            span_id: SpanId::random(&mut rand::thread_rng()),
+            span_id: SpanId::random(&mut rand::rng()),
             sampling_decision: self.sampling_decision,
         }
     }
@@ -91,7 +91,7 @@ impl TraceId {
     /// Returns a random trace ID that can be assumed to be globally unique if `rng` generates
     /// actually-random numbers.
     pub fn random<R: Rng>(rng: &mut R) -> Self {
-        TraceId(rng.r#gen::<NonZeroU128>().get())
+        TraceId(rng.random::<NonZeroU128>().get())
     }
 
     /// Returns true iff the trace ID is 0.
@@ -103,7 +103,7 @@ impl TraceId {
 impl SpanId {
     /// Returns a random span ID that can be assumed to be unique within a single trace.
     pub fn random<R: Rng>(rng: &mut R) -> Self {
-        SpanId(rng.r#gen::<NonZeroU64>().get())
+        SpanId(rng.random::<NonZeroU64>().get())
     }
 
     /// Returns true iff the span ID is 0.

From 4b7e4c605442b955e89045cc68dc67c91e27e1f6 Mon Sep 17 00:00:00 2001
From: Luke Carr <me+oss@carr.sh>
Date: Thu, 20 Nov 2025 13:15:07 +0000
Subject: [PATCH 2/7] Dervied `Default` for `SamplingDecision` to make clippy
 happy

Replaced manual `impl Default for SamplingDecision` with `#[derive(Default)]` to resolve clippy error.
---
 tarpc/src/trace.rs | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/tarpc/src/trace.rs b/tarpc/src/trace.rs
index 3e4fcf296..6d27c99e2 100644
--- a/tarpc/src/trace.rs
+++ b/tarpc/src/trace.rs
@@ -66,13 +66,14 @@ pub struct SpanId(u64);
 /// dependencies. On the other hand, if an upstream process has chosen to sample this trace, then
 /// the downstream samplers are expected to respect that decision and also sample the trace.
 /// Otherwise, the full trace would not be able to be reconstructed reliably.
-#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy, Default)]
 #[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
 #[repr(u8)]
 pub enum SamplingDecision {
     /// The associated span was sampled by its creating process. Child spans must also be sampled.
     Sampled,
     /// The associated span was not sampled by its creating process.
+    #[default]
     Unsampled,
 }
 
@@ -203,12 +204,6 @@ impl From<&opentelemetry::trace::SpanContext> for SamplingDecision {
     }
 }
 
-impl Default for SamplingDecision {
-    fn default() -> Self {
-        Self::Unsampled
-    }
-}
-
 /// Returned when a [`Context`] cannot be constructed from a [`Span`](tracing::Span).
 #[derive(Debug)]
 pub struct NoActiveSpan;

From a0e607c06ab8081a7e55006c4024d537b441bc5a Mon Sep 17 00:00:00 2001
From: Luke Carr <me+oss@carr.sh>
Date: Thu, 20 Nov 2025 15:51:14 +0000
Subject: [PATCH 3/7] Removed `patch` parts from Cargo dependency versions

---
 example-service/Cargo.toml | 12 ++++++------
 plugins/Cargo.toml         |  2 +-
 tarpc/Cargo.toml           | 18 +++++++++---------
 3 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/example-service/Cargo.toml b/example-service/Cargo.toml
index 0e7e33fc6..2d63f443d 100644
--- a/example-service/Cargo.toml
+++ b/example-service/Cargo.toml
@@ -15,19 +15,19 @@ description = "An example server built on tarpc."
 
 [dependencies]
 anyhow = "1.0"
-clap = { version = "4.5.53", features = ["derive"] }
+clap = { version = "4.5", features = ["derive"] }
 log = "0.4"
 futures = "0.3"
-opentelemetry = { version = "0.31.0" }
-opentelemetry-otlp = { version = "0.31.0", features = ["grpc-tonic"] }
+opentelemetry = { version = "0.31" }
+opentelemetry-otlp = { version = "0.31", features = ["grpc-tonic"] }
 rand = "0.9"
 tarpc = { version = "0.37", path = "../tarpc", features = ["full"] }
 tokio = { version = "1", features = ["macros", "net", "rt-multi-thread"] }
 tracing = { version = "0.1" }
-tracing-opentelemetry = "0.32.0"
+tracing-opentelemetry = "0.32"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-opentelemetry_sdk = { version = "0.31.0", features = ["rt-tokio"] }
-opentelemetry-semantic-conventions = "0.31.0"
+opentelemetry_sdk = { version = "0.31", features = ["rt-tokio"] }
+opentelemetry-semantic-conventions = "0.31"
 
 [lib]
 name = "service"
diff --git a/plugins/Cargo.toml b/plugins/Cargo.toml
index 8be746c26..9d0853433 100644
--- a/plugins/Cargo.toml
+++ b/plugins/Cargo.toml
@@ -28,7 +28,7 @@ syn = { version = "2.0", features = ["full", "extra-traits"] }
 proc-macro = true
 
 [dev-dependencies]
-assert-type-eq = "0.1.0"
+assert-type-eq = "0.1"
 futures = "0.3"
 serde = { version = "1.0", features = ["derive"] }
 tarpc = { path = "../tarpc", features = ["serde1"] }
diff --git a/tarpc/Cargo.toml b/tarpc/Cargo.toml
index e4de5518e..5ac0fde48 100644
--- a/tarpc/Cargo.toml
+++ b/tarpc/Cargo.toml
@@ -48,19 +48,19 @@ humantime = "2.3"
 pin-project = "1.1"
 rand = "0.9"
 serde = { optional = true, version = "1.0", features = ["derive"] }
-static_assertions = "1.1.0"
+static_assertions = "1.1"
 tarpc-plugins = { path = "../plugins", version = "0.14" }
 thiserror = "2.0"
 tokio = { version = "1", features = ["time"] }
-tokio-util = { version = "0.7.17", features = ["time"] }
+tokio-util = { version = "0.7", features = ["time"] }
 tokio-serde = { optional = true, version = "0.9" }
 tracing = { version = "0.1", default-features = false, features = [
     "attributes",
     "log",
 ] }
-tracing-opentelemetry = { version = "0.32.0", default-features = false }
-opentelemetry = { version = "0.31.0", default-features = false }
-opentelemetry-semantic-conventions = "0.31.0"
+tracing-opentelemetry = { version = "0.32", default-features = false }
+opentelemetry = { version = "0.31", default-features = false }
+opentelemetry-semantic-conventions = "0.31"
 
 [dev-dependencies]
 assert_matches = "1.5"
@@ -68,10 +68,10 @@ bincode = { version = "2.0", features = ["serde"] }
 bytes = { version = "1", features = ["serde"] }
 flate2 = "1.1"
 futures-test = "0.3"
-opentelemetry = { version = "0.31.0", default-features = false }
-opentelemetry-otlp = { version = "0.31.0", features = ["grpc-tonic"] }
-opentelemetry_sdk = { version = "0.31.0", features = ["rt-tokio"] }
-pin-utils = "0.1.0"
+opentelemetry = { version = "0.31", default-features = false }
+opentelemetry-otlp = { version = "0.31", features = ["grpc-tonic"] }
+opentelemetry_sdk = { version = "0.31", features = ["rt-tokio"] }
+pin-utils = "0.1"
 serde_bytes = "0.11"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tokio = { version = "1", features = ["full", "test-util", "tracing"] }

From 7edd8e40a7179b66720bcfc0903da3e5118aa509 Mon Sep 17 00:00:00 2001
From: Luke Carr <me+oss@carr.sh>
Date: Thu, 20 Nov 2025 16:04:44 +0000
Subject: [PATCH 4/7] Add comment justifying explicit `Result` ignore.

---
 tarpc/src/context.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tarpc/src/context.rs b/tarpc/src/context.rs
index f2a11bbab..fec15ac14 100644
--- a/tarpc/src/context.rs
+++ b/tarpc/src/context.rs
@@ -142,6 +142,9 @@ pub(crate) trait SpanExt {
 
 impl SpanExt for tracing::Span {
     fn set_context(&self, context: &Context) {
+        // Explicitly ignore the returned result because it either means that the span has
+        // already started, or the Otel layer is not present, so we don't mind if the result
+        // is an error we silently ignore.
         let _ = self.set_parent(
             opentelemetry::Context::new()
                 .with_remote_span_context(opentelemetry::trace::SpanContext::new(

From 810660704ae1f889de1c3fd8fdd52ebe27eec161 Mon Sep 17 00:00:00 2001
From: Luke Carr <me+oss@carr.sh>
Date: Thu, 20 Nov 2025 18:45:42 +0000
Subject: [PATCH 5/7] Bumped `actions/checkout` to `v6`.

---
 .github/workflows/main.yml | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 4b506ecfd..bfb542f85 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -42,7 +42,7 @@ jobs:
           - unix: "--features unix"
             serde-transport: ""
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
       - run: >
           cargo test --manifest-path tarpc/Cargo.toml
@@ -56,7 +56,7 @@ jobs:
     outputs:
       examples: ${{ steps.matrix.outputs.examples }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
       - id: matrix
         run: |
@@ -79,7 +79,7 @@ jobs:
       matrix:
         example: ${{ fromJSON(needs.list-examples.outputs.examples) }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
       - run: |
           cargo run --example "${{ matrix.example }}"
@@ -88,7 +88,7 @@ jobs:
     name: Rustfmt
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: rustfmt
@@ -98,7 +98,7 @@ jobs:
     name: Clippy
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy

From a3576ca7c06ee53f266b9eba976dfa64ebd9f8eb Mon Sep 17 00:00:00 2001
From: Luke Carr <me+oss@carr.sh>
Date: Thu, 20 Nov 2025 18:46:15 +0000
Subject: [PATCH 6/7] Updated `stderr` for `serde1/opt_out_serde` test case.

---
 tarpc/tests/compile_fail/serde1/opt_out_serde.stderr | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tarpc/tests/compile_fail/serde1/opt_out_serde.stderr b/tarpc/tests/compile_fail/serde1/opt_out_serde.stderr
index bdb46999c..630924f71 100644
--- a/tarpc/tests/compile_fail/serde1/opt_out_serde.stderr
+++ b/tarpc/tests/compile_fail/serde1/opt_out_serde.stderr
@@ -2,10 +2,15 @@ error[E0277]: the trait bound `FooRequest: serde::Serialize` is not satisfied
   --> tests/compile_fail/serde1/opt_out_serde.rs:12:40
    |
 12 |     tarpc::serde::Serialize::serialize(&x, f);
-   |     ---------------------------------- ^^ the trait `Serialize` is not implemented for `FooRequest`
+   |     ---------------------------------- ^^ unsatisfied trait bound
    |     |
    |     required by a bound introduced by this call
    |
+help: the trait `Serialize` is not implemented for `FooRequest`
+  --> tests/compile_fail/serde1/opt_out_serde.rs:5:1
+   |
+ 5 | #[tarpc::service(derive_serde = false)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for local types consider adding `#[derive(serde::Serialize)]` to your `FooRequest` type
    = note: for types from other crates check whether the crate offers a `serde` feature flag
    = help: the following other types implement trait `Serialize`:
@@ -18,3 +23,4 @@ error[E0277]: the trait bound `FooRequest: serde::Serialize` is not satisfied
              (T0, T1, T2, T3)
              (T0, T1, T2, T3, T4)
            and $N others
+   = note: this error originates in the attribute macro `tarpc::service` (in Nightly builds, run with -Z macro-backtrace for more info)

From b9362b3a29de92768b9fdce6899e247904c49e97 Mon Sep 17 00:00:00 2001
From: Luke Carr <me+oss@carr.sh>
Date: Thu, 20 Nov 2025 18:47:20 +0000
Subject: [PATCH 7/7] Bumped `actions/checkout` to `v6`.

---
 .github/workflows/pr_review.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/pr_review.yml b/.github/workflows/pr_review.yml
index 16397be5e..d848f0358 100644
--- a/.github/workflows/pr_review.yml
+++ b/.github/workflows/pr_review.yml
@@ -4,7 +4,7 @@ jobs:
   clippy:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: dtolnay/rust-toolchain@stable
       with:
         components: clippy