chore: relax msrv for most crates (#2378)

* chore: relax msrv for most crates

* Keep MSRV 1.75

* Allow to compile with 1.75 again

Author: acrrd

.github/workflows/CI.yml

@@ -183,8 +183,9 @@ jobs:
         rust-version: ${{ steps.msrv.outputs.version }}
     - uses: taiki-e/install-action@cargo-no-dev-deps
     - uses: Swatinem/rust-cache@v2
-    - run: cargo no-dev-deps --no-private check --all-features
-    - run: cargo no-dev-deps --no-private doc --no-deps --all-features
+    # we exlude crates that do not use rust-version = { workspace = true }
+    - run: cargo no-dev-deps --no-private check --all-features --workspace --exclude grpc --exclude tonic-protobuf\*
+    - run: cargo no-dev-deps --no-private doc --no-deps --all-features --workspace --exclude grpc --exclude tonic-protobuf\*
       env:
         RUSTDOCFLAGS: "-D warnings"
 

Cargo.toml

@@ -29,7 +29,7 @@ members = [
 resolver = "2"
 
 [workspace.package]
-rust-version = "1.86"
+rust-version = "1.75"
 
 [workspace.lints.rust]
 missing_debug_implementations = "warn"

grpc/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.9.0-alpha.1"
 edition = "2021"
 authors = ["gRPC Authors"]
 license = "MIT"
+rust-version = "1.86"
 
 [dependencies]
 bytes = "1.10.1"

tonic/src/codec/compression.rs

@@ -4,7 +4,7 @@ use bytes::{Buf, BufMut, BytesMut};
 use flate2::read::{GzDecoder, GzEncoder};
 #[cfg(feature = "deflate")]
 use flate2::read::{ZlibDecoder, ZlibEncoder};
-use std::fmt;
+use std::{borrow::Cow, fmt};
 #[cfg(feature = "zstd")]
 use zstd::stream::read::{Decoder, Encoder};
 
@@ -152,8 +152,8 @@ impl CompressionEncoding {
             b"identity" => Ok(None),
             other => {
                 let other = match std::str::from_utf8(other) {
-                    Ok(s) => s,
-                    Err(_) => &format!("{other:?}"),
+                    Ok(s) => Cow::Borrowed(s),
+                    Err(_) => Cow::Owned(format!("{other:?}")),
                 };
 
                 let mut status = Status::unimplemented(format!(