Rustup to the latest nightly

.travis.yml

@@ -2,7 +2,12 @@ language: rust
 rust: nightly
 sudo: false
 
-cache: cargo
+cache:
+  directories:
+    - $HOME/.cargo
+    - $HOME/.rustup
+before_cache:
+  - rm -rf /home/travis/.cargo/registry
 
 notifications:
   email:

ci/run.sh

@@ -33,8 +33,8 @@ case "${TRAVIS_OS_NAME}" in
         ;;
 esac
 
-# FIXME: Somehow we couldn't install semverver on Travis' Windows builder.
-if [ "${TRAVIS_OS_NAME}" = "windows" ]; then
+# FIXME: Sometimes we couldn't install semverver on Travis' Windows builder.
+if [ "${TRAVIS_OS_NAME}" != "linux" ]; then
     exit 0
 fi
 

src/mismatch.rs

@@ -236,7 +236,7 @@ impl<'a, 'tcx> TypeRelation<'tcx> for MismatchRelation<'a, 'tcx> {
                 }
             }
             (&TyKind::Tuple(as_), &TyKind::Tuple(bs)) => {
-                let _ = as_.iter().zip(bs).map(|(a, b)| self.relate(a, b));
+                let _ = as_.iter().zip(bs).map(|(a, b)| self.relate(&a, &b));
                 None
             }
             (&TyKind::Projection(a_data), &TyKind::Projection(b_data)) => {