async only on x86

src/shims/unix/linux/fs/epoll.rs

@@ -29,6 +29,10 @@ impl FileDescriptor for Epoll {
         Ok(Box::new(self.clone()))
     }
 
+    fn is_tty(&self) -> bool {
+        false
+    }
+
     fn close<'tcx>(
         self: Box<Self>,
         _communicate_allowed: bool,

src/shims/unix/linux/fs/event.rs

@@ -18,6 +18,10 @@ impl FileDescriptor for Event {
         Ok(Box::new(Event { val: self.val }))
     }
 
+    fn is_tty(&self) -> bool {
+        false
+    }
+
     fn write<'tcx>(
         &self,
         _communicate_allowed: bool,

src/shims/unix/linux/fs/socketpair.rs

@@ -16,6 +16,10 @@ impl FileDescriptor for SocketPair {
         Ok(Box::new(SocketPair))
     }
 
+    fn is_tty(&self) -> bool {
+        false
+    }
+
     fn close<'tcx>(
         self: Box<Self>,
         _communicate_allowed: bool,

tests/pass-dep/tokio_mvp.rs

@@ -2,4 +2,8 @@
 //@only-target-linux: the errors differ too much between platforms
 
 #[tokio::main]
+#[cfg(target_arch = "x86_64")]
 async fn main() {}
+
+#[cfg(target_arch = "not_x86_64")]
+fn main() {}