adapt to changes in the `start` lang item

1 files changed, 21 insertions, 0 deletions

diff --git a/cortex-m-rt/build.rs b/cortex-m-rt/build.rs
index 1d0160c..918cbfb 100644
--- a/cortex-m-rt/build.rs
+++ b/cortex-m-rt/build.rs
@@ -1,9 +1,30 @@
+extern crate chrono;
+extern crate rustc_version;
+
 use std::env;
 use std::fs::File;
 use std::io::Write;
 use std::path::PathBuf;
 
+use chrono::NaiveDate;
+
 fn main() {
+    let date: NaiveDate = rustc_version::version_meta()
+        .unwrap()
+        .commit_date
+        .unwrap()
+        .parse()
+        .unwrap();
+
+    if date <= NaiveDate::from_ymd(2017, 12, 26) {
+        let version = env!("CARGO_PKG_VERSION");
+        panic!(
+            "cortex-m-rt v{} doesn't support nightly-2017-12-27 and older; \
+             to use the current nightly switch to v0.3.7",
+            version
+        );
+    }
+
     let target = env::var("TARGET").unwrap();
 
     has_fpu(&target);