Pin build deps to avoid MSRV bump

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
 
         include:
           # Run check with MSRV as well
-          - rust: 1.65.0
+          - rust: 1.60.0
 
     steps:
       - uses: actions/checkout@v2

Cargo.toml

@@ -33,6 +33,12 @@ critical-section = "1.1"
 
 [build-dependencies]
 riscv-target = "0.1.2"
+# riscv-target depends on regex, which depends on memchr.
+# memchr bumped it's MSRV to 1.61 midway through 2.6.x releases
+# regex increased it's MSRV to 1.65 in release 1.10.x
+# pinning regex to 1.8.4 and memchr to 2.5.0 until we bump MSRV
+regex = "=1.8.4"
+memchr = "=2.5.0"
 
 [features]
 default = ["critical-section-impl"]

README.md

@@ -6,7 +6,7 @@ Matrix: [#bl602-rust:matrix.org](https://matrix.to/#/#bl602-rust:matrix.org)
 
 ## Minimum Supported Rust Version
 
-The minimum supported Rust version (MSRV) for this project is Rust **v1.65.0**. The
+The minimum supported Rust version (MSRV) for this project is Rust **v1.60.0**. The
 project might build on earlier versions, but this is the earliest version that
 is expected to work.
 

src/delay.rs

@@ -9,15 +9,15 @@ use embedded_hal_zero::blocking::delay::{DelayMs as DelayMsZero, DelayUs as Dela
 /// bit-banging protocols, etc
 #[derive(Copy, Clone)]
 pub struct McycleDelay {
+    /// System clock frequency, used to convert clock cycles
+    /// into real-world time values
     core_frequency: u32,
 }
 
 impl McycleDelay {
     /// Constructs the delay provider based on core clock frequency `freq`
     pub fn new(freq: u32) -> Self {
-        Self {
-            /// System clock frequency, used to convert clock cycles
-            /// into real-world time values
+        Self {        
             core_frequency: freq,
         }
     }