Bump MSRV to 1.91.0 (#4487)

## Motivation and Context
Bumps MSRV to 1.91.0

## Description
Updates MSRV to 1.91.0 and fixes minor clippy lints introduced in Rust
1.91.

## Testing
- CI

## Checklist
- [x] For changes to the smithy-rs codegen or runtime crates, I have
created a changelog entry Markdown file in the `.changelog` directory,
specifying "client," "server," or both in the `applies_to` key.
- [x] For changes to the AWS SDK, generated SDK code, or SDK runtime
crates, I have created a changelog entry Markdown file in the
`.changelog` directory, specifying "aws-sdk-rust" in the `applies_to`
key.

----

_By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice._

Author: vcjana

.changelog/bump-msrv-1.91.md

@@ -0,0 +1,9 @@
+---
+applies_to: ["client", "server", "aws-sdk-rust"]
+authors: ["vcjana"]
+references: []
+breaking: true
+new_feature: false
+bug_fix: false
+---
+Upgrade MSRV to Rust 1.91.0.

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ on:
         required: false
 
 env:
-  rust_version: 1.88.0
+  rust_version: 1.91.0
   rust_toolchain_components: clippy,rustfmt
   ENCRYPTED_DOCKER_PASSWORD: ${{ secrets.ENCRYPTED_DOCKER_PASSWORD }}
   DOCKER_LOGIN_TOKEN_PASSPHRASE: ${{ secrets.DOCKER_LOGIN_TOKEN_PASSPHRASE }}
@@ -253,20 +253,23 @@ jobs:
           build_aws_exclude: ''
           build_smithy_rs_exclude: --exclude aws-smithy-http-server-python --exclude aws-smithy-http-server-typescript --exclude aws-smithy-experimental --exclude aws-smithy-http-client
           test_smithy_rs_features: --all-features
+          test_aws_features: --all-features
           test_aws_exclude: ''
           test_smithy_rs_exclude: --exclude aws-smithy-http-server-python --exclude aws-smithy-http-server-typescript --exclude aws-smithy-experimental --exclude aws-smithy-http-client
         - target: powerpc-unknown-linux-gnu
           build_smithy_rs_features: ''
           build_aws_exclude: --exclude aws-inlineable
           build_smithy_rs_exclude: --exclude aws-smithy-http-server-python --exclude aws-smithy-http-server-typescript --exclude aws-smithy-experimental --exclude aws-smithy-http-client
           test_smithy_rs_features: ''
+          test_aws_features: ''
           test_aws_exclude: --exclude aws-inlineable
           test_smithy_rs_exclude: --exclude aws-smithy-http-server-python --exclude aws-smithy-http-server-typescript --exclude aws-smithy-experimental --exclude aws-smithy-http-client
         - target: powerpc64-unknown-linux-gnu
           build_smithy_rs_features: ''
           build_aws_exclude: --exclude aws-inlineable
           build_smithy_rs_exclude: --exclude aws-smithy-http-server-python --exclude aws-smithy-http-server-typescript --exclude aws-smithy-experimental --exclude aws-smithy-http-client
           test_smithy_rs_features: ''
+          test_aws_features: ''
           test_aws_exclude: --exclude aws-inlineable
           test_smithy_rs_exclude: --exclude aws-smithy-http-server-python --exclude aws-smithy-http-server-typescript --exclude aws-smithy-experimental --exclude aws-smithy-http-client
     steps:
@@ -331,7 +334,7 @@ jobs:
       run: cross test --target ${{ matrix.target }} --manifest-path "rust-runtime/Cargo.toml" ${{ matrix.test_smithy_rs_exclude }} --workspace ${{ matrix.test_smithy_rs_features }}
     - name: Test AWS rust-runtime crates
       shell: bash
-      run: cross test --target ${{ matrix.target }} --manifest-path "aws/rust-runtime/Cargo.toml" ${{ matrix.test_aws_exclude }} --workspace
+      run: cross test --target ${{ matrix.target }} --manifest-path "aws/rust-runtime/Cargo.toml" ${{ matrix.test_aws_exclude }} --workspace ${{ matrix.test_aws_features }}
 
   # Run the canary against generated SDKs
   #

.github/workflows/claim-crate-names.yml

@@ -10,7 +10,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  rust_version: 1.88.0
+  rust_version: 1.91.0
 
 name: Claim unpublished crate names on crates.io
 run-name: ${{ github.workflow }}

.github/workflows/github-pages.yml

@@ -8,7 +8,7 @@ on:
 name: Update GitHub Pages
 
 env:
-  rust_version: 1.88.0
+  rust_version: 1.91.0
 
 # Allow only one doc pages build to run at a time for the entire smithy-rs repo
 concurrency:

.github/workflows/pull-request-bot.yml

@@ -35,7 +35,7 @@ env:
   apt_dependencies: libssl-dev gnuplot jq
   java_version: 17
   rust_toolchain_components: clippy,rustfmt
-  rust_nightly_version: nightly-2025-05-04
+  rust_nightly_version: nightly-2025-10-18
   ENCRYPTED_DOCKER_PASSWORD: ${{ secrets.ENCRYPTED_DOCKER_PASSWORD }}
   DOCKER_LOGIN_TOKEN_PASSPHRASE: ${{ secrets.DOCKER_LOGIN_TOKEN_PASSPHRASE }}
 

.github/workflows/release.yml

@@ -10,7 +10,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  rust_version: 1.88.0
+  rust_version: 1.91.0
 
 name: Release smithy-rs
 on:

.github/workflows/update-sdk-next.yml

@@ -46,7 +46,7 @@ jobs:
     - name: Set up Rust
       uses: dtolnay/rust-toolchain@master
       with:
-        toolchain: 1.88.0
+        toolchain: 1.91.0
     - name: Delete old SDK
       run: |
     - name: Generate a fresh SDK

aws/codegen-aws-sdk/src/test/kotlin/software/amazon/smithy/rustsdk/EndpointOverrideMetricDecoratorTest.kt

@@ -88,7 +88,6 @@ class EndpointOverrideMetricDecoratorTest {
         awsSdkIntegrationTest(
             model,
             testParams,
-            environment = mapOf("RUSTUP_TOOLCHAIN" to "1.88.0"),
         ) { context, rustCrate ->
             val rc = context.runtimeConfig
             val moduleName = context.moduleUseName()
@@ -104,16 +103,16 @@ class EndpointOverrideMetricDecoratorTest {
                         use $moduleName::Client;
                         use #{capture_request};
                         use #{assert_ua_contains_metric_values};
-                        
+
                         let (http_client, rcvr) = capture_request(None);
-                        
+
                         // Create SdkConfig with endpoint URL
                         let sdk_config = #{SdkConfig}::builder()
                             .region(Region::new("us-east-1"))
                             .endpoint_url("https://sdk-custom.example.com")
                             .http_client(http_client.clone())
                             .build();
-                        
+
                         // Create client from SdkConfig
                         let client = Client::new(&sdk_config);
 
@@ -136,7 +135,7 @@ class EndpointOverrideMetricDecoratorTest {
                             .headers()
                             .get("x-amz-user-agent")
                             .expect("x-amz-user-agent header missing");
-                        
+
                         assert_ua_contains_metric_values(user_agent, &["N"]);
                         """,
                         *preludeScope,
@@ -156,7 +155,6 @@ class EndpointOverrideMetricDecoratorTest {
         awsSdkIntegrationTest(
             model,
             testParams,
-            environment = mapOf("RUSTUP_TOOLCHAIN" to "1.88.0"),
         ) { context, rustCrate ->
             val rc = context.runtimeConfig
             val moduleName = context.moduleUseName()
@@ -171,9 +169,9 @@ class EndpointOverrideMetricDecoratorTest {
                         use $moduleName::config::{Credentials, Region, SharedCredentialsProvider};
                         use $moduleName::{Config, Client};
                         use #{capture_request};
-                        
+
                         let (http_client, rcvr) = capture_request(None);
-                        
+
                         // Create config WITHOUT endpoint override
                         let config = Config::builder()
                             .credentials_provider(SharedCredentialsProvider::new(Credentials::for_tests()))

aws/rust-runtime/Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "aws-config"
-version = "1.8.13"
+version = "1.8.14"
 authors = [
     "AWS Rust SDK Team <aws-sdk-rust@amazon.com>",
     "Russell Cohen <rcoh@amazon.com>",
@@ -10,7 +10,7 @@ edition = "2021"
 exclude = ["test-data/*", "integration-tests/*"]
 license = "Apache-2.0"
 repository = "https://github.com/smithy-lang/smithy-rs"
-rust-version = "1.88"
+rust-version = "1.91"
 
 [features]
 behavior-version-latest = []