Lock MSRV to 1.60 and validate in CI (#362)

* Lock MSRV to 1.60 and validate in CI

Prevent inadvertently bumping MSRV in PRs by checking against MSRV in
the CI, to disallow any large bumps without rationale.  Rust 1.60 is 7
months old at the time of writing, and also required by `winit` which
uses `android-ndk-rs`, hence must be compatible with it.

This does not mean that we cannot bump MSRV at all, but we must remain a
tad conservative; at the same time setting [`rust-version`] in the
manifest provides everyone on Rust 1.56 and higher a helpful error
message when their version is lower than what we require.

[`rust-version`]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field

* ndk-build: Bump quick-xml to 0.26 to solve accidental MSRV bump

Git history suggests that `quick-xml` backed out of an (un?)intentional
MSRV bump and is now back at Rust 1.46; well below our MSRV needed for
`winit`.

.github/workflows/rust.yml

@@ -36,6 +36,20 @@ jobs:
         # also compile cleanly under this target.
         args: --all --all-targets --all-features --target aarch64-linux-android -- -Dwarnings
 
+  check_msrv:
+    name: Check MSRV (1.60.0)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: dtolnay/rust-toolchain@1.60.0
+        with:
+          target: aarch64-linux-android
+      - uses: actions-rs/cargo@v1
+        with:
+          command: check
+          # See comment above about using one of our supported targets.
+          args: --workspace --all-targets --all-features --target aarch64-linux-android
+
   build:
     strategy:
       fail-fast: false

README.md

@@ -1,6 +1,7 @@
 # Rust on Android
 
-[![Rust](https://github.com/rust-windowing/android-ndk-rs/workflows/Rust/badge.svg)](https://github.com/rust-windowing/android-ndk-rs/actions) ![MIT license](https://img.shields.io/badge/License-MIT-green.svg) ![APACHE2 license](https://img.shields.io/badge/License-APACHE2-green.svg)
+[![Rust](https://github.com/rust-windowing/android-ndk-rs/workflows/Rust/badge.svg)](https://github.com/rust-windowing/android-ndk-rs/actions) ![MIT license](https://img.shields.io/badge/License-MIT-green.svg) ![APACHE2 license](https://img.shields.io/badge/License-APACHE2-green.svg) [![MSRV](https://img.shields.io/badge/rustc-1.60.0+-ab6000.svg)](https://blog.rust-lang.org/2022/04/07/Rust-1.60.0.html)
+
 
 Libraries and tools for Rust programming on Android targets:
 

cargo-apk/Cargo.toml

@@ -9,6 +9,7 @@ keywords = ["android", "ndk", "apk"]
 documentation = "https://docs.rs/cargo-apk"
 homepage = "https://github.com/rust-windowing/android-ndk-rs"
 repository = "https://github.com/rust-windowing/android-ndk-rs"
+rust-version = "1.60"
 
 [dependencies]
 anyhow = "1.0.57"

ndk-build/Cargo.toml

@@ -9,11 +9,12 @@ keywords = ["android", "ndk", "apk"]
 documentation = "https://docs.rs/ndk-build"
 homepage = "https://github.com/rust-windowing/android-ndk-rs"
 repository = "https://github.com/rust-windowing/android-ndk-rs"
+rust-version = "1.60"
 
 [dependencies]
 dirs = "4"
 dunce = "1"
-quick-xml = { version = "0.25", features = ["serialize"] }
+quick-xml = { version = "0.26", features = ["serialize"] }
 serde = { version = "1", features = ["derive"] }
 thiserror = "1"
 which = "4"

ndk-context/Cargo.toml

@@ -9,3 +9,4 @@ keywords = ["android", "ndk", "apk", "jni"]
 documentation = "https://docs.rs/ndk-context"
 homepage = "https://github.com/rust-windowing/android-ndk-rs"
 repository = "https://github.com/rust-windowing/android-ndk-rs"
+rust-version = "1.60"

ndk-glue/Cargo.toml

@@ -10,6 +10,7 @@ readme = "README.md"
 documentation = "https://docs.rs/ndk-glue"
 homepage = "https://github.com/rust-windowing/android-ndk-rs"
 repository = "https://github.com/rust-windowing/android-ndk-rs"
+rust-version = "1.60"
 
 [dependencies]
 android_logger = { version = "0.11", optional = true }

ndk-macro/Cargo.toml

@@ -10,6 +10,7 @@ readme = "README.md"
 documentation = "https://docs.rs/ndk-macro"
 homepage = "https://github.com/rust-windowing/android-ndk-rs"
 repository = "https://github.com/rust-windowing/android-ndk-rs"
+rust-version = "1.60"
 
 [lib]
 proc-macro = true

ndk-sys/Cargo.toml

@@ -10,6 +10,7 @@ readme = "../README.md"
 documentation = "https://docs.rs/android-ndk-sys"
 homepage = "https://github.com/rust-windowing/android-ndk-rs"
 repository = "https://github.com/rust-windowing/android-ndk-rs"
+rust-version = "1.60"
 
 [dependencies]
 jni-sys = "0.3.0"

ndk/Cargo.toml

@@ -10,6 +10,7 @@ readme = "../README.md"
 documentation = "https://docs.rs/android-ndk"
 homepage = "https://github.com/rust-windowing/android-ndk-rs"
 repository = "https://github.com/rust-windowing/android-ndk-rs"
+rust-version = "1.60"
 
 [features]
 all = ["audio", "bitmap","media", "api-level-30"]