Issues when building async_std in travis-ci

Hi there,

I have a crate which unit tests depend on async_std. Those tests compile and run fine on my local windows machine, but on the travis-ci pipeline I got the following issue:

Compiling async-std v1.6.4
error[E0046]: not all trait items implemented, missing: `as_flags`
   --> /home/travis/.cargo/registry/src/github.com-1ecc6299db9ec823/async-std-1.6.4/src/fs/open_options.rs:303:5
    |
303 |     impl OpenOptionsExt for OpenOptions {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `as_flags` in implementation
    |
    = help: implement the missing item: `fn as_flags(&self) -> std::result::Result<i32, futures_io::Error> { todo!() }`

Is this kind of a regression and if so, which version is then best to use currently ?

See here. Consider building on stable.

Hey,
thanks for the link to the issue. Unfortunately I can‘t just use stable. The reason is, that I need to cross compile to aarch64-unknown-none.

I guess I need to specify a previous nightly version than for my builds.

I have the same problem