Run miri on CI

.github/workflows/ci.yml

@@ -51,6 +51,27 @@ jobs:
           command: test
           args: ${{ matrix.features }}
 
+  miri:
+    name: Miri
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - nightly
+        features:
+          - --all-features
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          override: true
+          components: miri
+      - uses: actions-rs/cargo@v1
+        with:
+          command: miri
+          args: test ${{ matrix.features }}
+
   test-msrv:
     name: Test Suite
     runs-on: ubuntu-latest

src/error.rs

@@ -564,7 +564,8 @@ where
     E: StdError + Send + Sync + 'static,
 {
     // Attach ErrorImpl<E>'s native StdError vtable. The StdError impl is below.
-    mem::transmute::<Box<ErrorImpl<()>>, Box<ErrorImpl<E>>>(e)
+    let unerased: Box<ErrorImpl<E>> = Box::from_raw(Box::into_raw(e).cast());
+    unerased
 }
 
 // Safety: requires layout of *e to match ErrorImpl<E>.
@@ -611,16 +612,10 @@ where
     // Called after downcasting by value to either the D or the E and doing a
     // ptr::read to take ownership of that value.
     if TypeId::of::<D>() == target {
-        let unerased = mem::transmute::<
-            Box<ErrorImpl<()>>,
-            Box<ErrorImpl<ContextError<ManuallyDrop<D>, E>>>,
-        >(e);
+        let unerased: Box<ErrorImpl<ContextError<ManuallyDrop<D>, E>>> = Box::from_raw(Box::into_raw(e).cast());
         drop(unerased);
     } else {
-        let unerased = mem::transmute::<
-            Box<ErrorImpl<()>>,
-            Box<ErrorImpl<ContextError<D, ManuallyDrop<E>>>>,
-        >(e);
+        let unerased: Box<ErrorImpl<ContextError<D, ManuallyDrop<E>>>> = Box::from_raw(Box::into_raw(e).cast());
         drop(unerased);
     }
 }
@@ -649,17 +644,11 @@ where
     // Called after downcasting by value to either the D or one of the causes
     // and doing a ptr::read to take ownership of that value.
     if TypeId::of::<D>() == target {
-        let unerased = mem::transmute::<
-            Box<ErrorImpl<()>>,
-            Box<ErrorImpl<ContextError<ManuallyDrop<D>, Report>>>,
-        >(e);
+        let unerased: Box<ErrorImpl<ContextError<ManuallyDrop<D>, Report>>> = Box::from_raw(Box::into_raw(e).cast());
         // Drop the entire rest of the data structure rooted in the next Report.
         drop(unerased);
     } else {
-        let unerased = mem::transmute::<
-            Box<ErrorImpl<()>>,
-            Box<ErrorImpl<ContextError<D, ManuallyDrop<Report>>>>,
-        >(e);
+        let unerased: Box<ErrorImpl<ContextError<D, ManuallyDrop<Report>>>> = Box::from_raw(Box::into_raw(e).cast());
         // Read out a ManuallyDrop<Box<ErrorImpl<()>>> from the next error.
         let inner = ptr::read(&unerased._object.error.inner);
         drop(unerased);

tests/compiletest.rs

@@ -1,4 +1,5 @@
 #[rustversion::attr(not(nightly), ignore)]
+#[cfg_attr(miri, ignore)]
 #[test]
 fn ui() {
     let t = trybuild::TestCases::new();

tests/test_location.rs

@@ -39,6 +39,7 @@ impl eyre::EyreHandler for LocationHandler {
     }
 }
 
+#[cfg_attr(miri, ignore)]
 #[test]
 fn test_wrap_err() {
     let _ = eyre::set_hook(Box::new(|_e| {
@@ -54,6 +55,7 @@ fn test_wrap_err() {
     println!("{:?}", err);
 }
 
+#[cfg_attr(miri, ignore)]
 #[test]
 fn test_wrap_err_with() {
     let _ = eyre::set_hook(Box::new(|_e| {
@@ -69,6 +71,7 @@ fn test_wrap_err_with() {
     println!("{:?}", err);
 }
 
+#[cfg_attr(miri, ignore)]
 #[test]
 fn test_context() {
     let _ = eyre::set_hook(Box::new(|_e| {
@@ -84,6 +87,7 @@ fn test_context() {
     println!("{:?}", err);
 }
 
+#[cfg_attr(miri, ignore)]
 #[test]
 fn test_with_context() {
     let _ = eyre::set_hook(Box::new(|_e| {

tests/test_pyo3.rs

@@ -17,6 +17,7 @@ fn h() -> Result<()> {
     g().wrap_err("g failed")
 }
 
+#[cfg_attr(miri, ignore)]
 #[test]
 fn test_pyo3_exception_contents() {
     use pyo3::types::IntoPyDict;