Merge pull request tock#4275 from tock/hail-stable-rustc-version

Hail: Specify minimum stable rustc version, makefile auto updates if needed

boards/Makefile.common

@@ -131,6 +131,20 @@ ifneq ($(shell $(RUSTUP) target list | grep "$(TARGET) (installed)"),$(TARGET) (
   $(shell sleep 5)
   $(shell $(RUSTUP) target add $(TARGET))
 endif
+
+# If the board the user is compiling is using the stable toolchain, verify that
+# the user's stable rustc toolchain is new enough to compile the board. If the
+# toolchain is too old, wait 5 seconds and then install for the user.
+ifneq ($(shell $(RUSTUP) show active-toolchain | grep "stable"),)
+  # If the error from running --version shows a version mismatch we know the
+  # installed toolchain is too old.
+  ifneq ($(shell $(CARGO) rustc -- --version 2>&1 | grep "is not supported by the following packages"),)
+    $(warning Your stable rustc is older than the MSRV of this board)
+    $(warning make will update your stable rustc in 5s)
+    $(shell sleep 5)
+    DUMMY := $(shell $(RUSTUP) update)
+  endif
+endif
 endif # $(NO_RUSTUP)
 
 # If the user is using the standard toolchain provided as part of the llvm-tools

boards/hail/Cargo.toml

@@ -8,6 +8,7 @@ version.workspace = true
 authors.workspace = true
 build = "../build.rs"
 edition.workspace = true
+rust-version = "1.83"
 
 [dependencies]
 components = { path = "../components" }