Add defmt::Format bound to error types in embedded-io

Author: JalonWong

.github/workflows/clippy.yml

@@ -14,4 +14,5 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
-      - run: cargo clippy --all-features -- --deny=warnings
+      - run: cargo clippy --workspace --exclude=embedded-io-adapters --all-features -- --deny=warnings
+      - run: cargo clippy --package=embedded-io-adapters --all-features -- --deny=warnings

.github/workflows/rustdoc.yml

@@ -15,4 +15,5 @@ jobs:
         with:
           toolchain: nightly-2024-07-26
       # tokio/net required to workaround https://github.com/tokio-rs/tokio/issues/6165
-      - run: RUSTDOCFLAGS="--deny=warnings --cfg=docsrs" cargo doc --all-features --features tokio/net
+      - run: RUSTDOCFLAGS="--deny=warnings --cfg=docsrs" cargo doc --workspace --exclude=embedded-io-adapters --all-features --features tokio/net
+      - run: RUSTDOCFLAGS="--deny=warnings --cfg=docsrs" cargo doc --package=embedded-io-adapters --all-features --features tokio/net

.github/workflows/test.yml

@@ -17,13 +17,14 @@ jobs:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
       - run: cargo test --workspace
-  
+
   test-all-features:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
-      - run: cargo test --workspace --all-features
+      - run: cargo test --workspace --exclude=embedded-io-adapters --all-features
+      - run: cargo test --package=embedded-io-adapters --all-features
 
   build-nostd:
     runs-on: ubuntu-latest
@@ -43,4 +44,5 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/[email protected]
-      - run: cargo test --workspace --all-features
+      - run: cargo test --workspace --exclude=embedded-io-adapters --all-features
+      - run: cargo test --package=embedded-io-adapters --all-features

embedded-io/src/lib.rs

@@ -218,6 +218,10 @@ impl Error for std::io::Error {
 /// which might be different types.
 pub trait ErrorType {
     /// Error type of all the IO operations on this type.
+    #[cfg(feature = "defmt")]
+    type Error: Error + defmt::Format;
+    /// Error type of all the IO operations on this type.
+    #[cfg(not(feature = "defmt"))]
     type Error: Error;
 }