diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index a10868b84d264..ae53c054e414b 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -771,7 +771,11 @@ impl Build {
     fn release(&self, num: &str) -> String {
         match &self.config.channel[..] {
             "stable" => num.to_string(),
-            "beta" => format!("{}-beta.{}", num, self.beta_prerelease_version()),
+            "beta" => if self.rust_info.is_git() {
+                format!("{}-beta.{}", num, self.beta_prerelease_version())
+            } else {
+                format!("{}-beta", num)
+            },
             "nightly" => format!("{}-nightly", num),
             _ => format!("{}-dev", num),
         }
diff --git a/src/librustc_trans/mir/constant.rs b/src/librustc_trans/mir/constant.rs
index d836d796c4113..e6917a964f42f 100644
--- a/src/librustc_trans/mir/constant.rs
+++ b/src/librustc_trans/mir/constant.rs
@@ -140,7 +140,10 @@ impl<'a, 'tcx> Const<'tcx> {
                 }
             }
             _ => {
-                const_get_elt(self.llval, layout.llvm_field_index(i))
+                match layout.fields {
+                    layout::FieldPlacement::Union(_) => self.llval,
+                    _ => const_get_elt(self.llval, layout.llvm_field_index(i)),
+                }
             }
         }
     }
diff --git a/src/librustc_trans/type_of.rs b/src/librustc_trans/type_of.rs
index 8d9bc07fe5630..e57d027dc8237 100644
--- a/src/librustc_trans/type_of.rs
+++ b/src/librustc_trans/type_of.rs
@@ -57,7 +57,9 @@ fn uncached_llvm_type<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
         ty::TyClosure(..) |
         ty::TyGenerator(..) |
         ty::TyAdt(..) |
-        ty::TyDynamic(..) |
+        // FIXME(eddyb) producing readable type names for trait objects can result
+        // in problematically distinct types due to HRTB and subtyping (see #47638).
+        // ty::TyDynamic(..) |
         ty::TyForeign(..) |
         ty::TyStr => {
             let mut name = String::with_capacity(32);
diff --git a/src/test/codegen/function-arguments.rs b/src/test/codegen/function-arguments.rs
index f8945a6ee8d93..0e98d3f9050a8 100644
--- a/src/test/codegen/function-arguments.rs
+++ b/src/test/codegen/function-arguments.rs
@@ -122,13 +122,13 @@ pub fn unsafe_slice(_: &[UnsafeInner]) {
 pub fn str(_: &[u8]) {
 }
 
-// CHECK: @trait_borrow(%"core::ops::drop::Drop"* nonnull %arg0.0, {}* noalias nonnull readonly %arg0.1)
+// CHECK: @trait_borrow({}* nonnull %arg0.0, {}* noalias nonnull readonly %arg0.1)
 // FIXME #25759 This should also have `nocapture`
 #[no_mangle]
 pub fn trait_borrow(_: &Drop) {
 }
 
-// CHECK: @trait_box(%"core::ops::drop::Drop"* noalias nonnull, {}* noalias nonnull readonly)
+// CHECK: @trait_box({}* noalias nonnull, {}* noalias nonnull readonly)
 #[no_mangle]
 pub fn trait_box(_: Box<Drop>) {
 }
diff --git a/src/test/run-pass/issue-47638.rs b/src/test/run-pass/issue-47638.rs
new file mode 100644
index 0000000000000..6f627b2a3c137
--- /dev/null
+++ b/src/test/run-pass/issue-47638.rs
@@ -0,0 +1,18 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn id<'c, 'b>(f: &'c &'b Fn(&i32)) -> &'c &'b Fn(&'static i32) {
+    f
+}
+
+fn main() {
+    let f: &Fn(&i32) = &|x| {};
+    id(&f);
+}
diff --git a/src/test/run-pass/union/union-const-eval-field.rs b/src/test/run-pass/union/union-const-eval-field.rs
new file mode 100644
index 0000000000000..f83f49f298b90
--- /dev/null
+++ b/src/test/run-pass/union/union-const-eval-field.rs
@@ -0,0 +1,45 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(const_fn)]
+
+type Field1 = i32;
+type Field2 = f32;
+type Field3 = i64;
+
+union DummyUnion {
+    field1: Field1,
+    field2: Field2,
+    field3: Field3,
+}
+
+const FLOAT1_AS_I32: i32 = 1065353216;
+const UNION: DummyUnion = DummyUnion { field1: FLOAT1_AS_I32 };
+
+const fn read_field1() -> Field1 {
+    const FIELD1: Field1 = unsafe { UNION.field1 };
+    FIELD1
+}
+
+const fn read_field2() -> Field2 {
+    const FIELD2: Field2 = unsafe { UNION.field2 };
+    FIELD2
+}
+
+const fn read_field3() -> Field3 {
+    const FIELD3: Field3 = unsafe { UNION.field3 };
+    FIELD3
+}
+
+fn main() {
+    assert_eq!(read_field1(), FLOAT1_AS_I32);
+    assert_eq!(read_field2(), 1.0);
+    assert_eq!(read_field3(), unsafe { UNION.field3 });
+}
diff --git a/src/tools/cargo b/src/tools/cargo
index 64326d735a0c8..8c93e08953646 160000
--- a/src/tools/cargo
+++ b/src/tools/cargo
@@ -1 +1 @@
-Subproject commit 64326d735a0c883ad6aa0a2c49fe12b5b61307e1
+Subproject commit 8c93e089536467783957fec23b0f2627bb6ce357