Compiling bitflags v1.2.1
   Compiling futures-task v0.3.1
   Compiling slab v0.4.2
   Compiling pin-utils v0.1.0-alpha.4
   Compiling futures-core v0.3.1
error[E0432]: unresolved import `core::task::Context`
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:7:12
  |
7 |     task::{Context, Poll},
  |            ^^^^^^^ no `Context` in `task`

error[E0432]: unresolved import `core::task::Context`
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/lib.rs:57:22
   |
57 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
   |                      ^^^^^^^ no `Context` in `task`

error[E0658]: use of unstable library feature 'alloc': this library is unlikely to be stabilized in its current form or name (see issue #27783)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/lib.rs:20:1
   |
20 | extern crate alloc;
   | ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/lib.rs:57:31
   |
57 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
   |                               ^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/lib.rs:57:37
   |
57 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
   |                                     ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/lib.rs:57:44
   |
57 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
   |                                            ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/lib.rs:57:54
   |
57 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
   |                                                      ^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:4:5
  |
4 |     future::Future,
  |     ^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:7:21
  |
7 |     task::{Context, Poll},
  |                     ^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:17:23
   |
17 |     future: *mut (dyn Future<Output = T> + 'static),
   |                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:18:34
   |
18 |     drop_fn: unsafe fn(*mut (dyn Future<Output = T> + 'static)),
   |                                  ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:29:56
   |
29 | unsafe fn remove_future_lifetime<'a, T>(ptr: *mut (dyn Future<Output = T> + 'a))
   |                                                        ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:30:18
   |
30 |     -> *mut (dyn Future<Output = T> + 'static)
   |                  ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:36:65
   |
36 | unsafe fn remove_drop_lifetime<'a, T>(ptr: unsafe fn (*mut (dyn Future<Output = T> + 'a)))
   |                                                                 ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:37:28
   |
37 |     -> unsafe fn(*mut (dyn Future<Output = T> + 'static))
   |                            ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:81:5
   |
81 |     type Output = T;
   |     ^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:84:5
   |
84 | /     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
85 | |         unsafe {
86 | |             Pin::new_unchecked(&mut *self.future).poll(cx)
87 | |         }
88 | |     }
   | |_____^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:80:9
   |
80 | impl<T> Future for LocalFutureObj<'_, T> {
   |         ^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:129:5
    |
129 |     type Output = T;
    |     ^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:132:5
    |
132 | /     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
133 | |         Pin::new( &mut self.0 ).poll(cx)
134 | |     }
    | |_____^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:128:9
    |
128 | impl<T> Future for FutureObj<'_, T> {
    |         ^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:183:8
    |
183 |     F: Future<Output = T> + Unpin + 'a
    |        ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:192:60
    |
192 | unsafe impl<'a, T> UnsafeFutureObj<'a, T> for &'a mut (dyn Future<Output = T> + Unpin + 'a)
    |                                                            ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:203:8
    |
203 |     F: Future<Output = T> + 'a
    |        ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:212:64
    |
212 | unsafe impl<'a, T> UnsafeFutureObj<'a, T> for Pin<&'a mut (dyn Future<Output = T> + 'a)>
    |                                                                ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:158:36
    |
158 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a);
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:178:35
    |
178 |     unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a));
    |                                   ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:84:64
   |
84 |     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
   |                                                                ^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:132:64
    |
132 |     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<T> {
    |                                                                ^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:185:36
    |
185 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:186:26
    |
186 |         self as *mut dyn Future<Output = T>
    |                          ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:189:36
    |
189 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:194:36
    |
194 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:195:26
    |
195 |         self as *mut dyn Future<Output = T>
    |                          ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:198:36
    |
198 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:205:36
    |
205 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:206:55
    |
206 |         unsafe { self.get_unchecked_mut() as *mut dyn Future<Output = T> }
    |                                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:209:36
    |
209 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:214:36
    |
214 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:215:55
    |
215 |         unsafe { self.get_unchecked_mut() as *mut dyn Future<Output = T> }
    |                                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:218:36
    |
218 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                    ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:227:18
    |
227 |         where F: Future<Output = T> + 'a
    |                  ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:238:63
    |
238 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + 'a> {
    |                                                               ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:248:63
    |
248 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + Send + 'a> {
    |                                                               ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:260:12
    |
260 |         F: Future<Output = T> + 'a
    |            ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:273:67
    |
273 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + 'a>> {
    |                                                                   ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:285:67
    |
285 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + Send + 'a>> {
    |                                                                   ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:297:17
    |
297 |     impl<'a, F: Future<Output = ()> + Send + 'a> From<Box<F>> for FutureObj<'a, ()> {
    |                 ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:303:27
    |
303 |     impl<'a> From<Box<dyn Future<Output = ()> + Send + 'a>> for FutureObj<'a, ()> {
    |                           ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:309:17
    |
309 |     impl<'a, F: Future<Output = ()> + Send + 'a> From<Pin<Box<F>>> for FutureObj<'a, ()> {
    |                 ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:315:31
    |
315 |     impl<'a> From<Pin<Box<dyn Future<Output = ()> + Send + 'a>>> for FutureObj<'a, ()> {
    |                               ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:321:17
    |
321 |     impl<'a, F: Future<Output = ()> + 'a> From<Box<F>> for LocalFutureObj<'a, ()> {
    |                 ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:327:27
    |
327 |     impl<'a> From<Box<dyn Future<Output = ()> + 'a>> for LocalFutureObj<'a, ()> {
    |                           ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:333:17
    |
333 |     impl<'a, F: Future<Output = ()> + 'a> From<Pin<Box<F>>> for LocalFutureObj<'a, ()> {
    |                 ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:339:31
    |
339 |     impl<'a> From<Pin<Box<dyn Future<Output = ()> + 'a>>> for LocalFutureObj<'a, ()> {
    |                               ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:229:40
    |
229 |         fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                        ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:233:39
    |
233 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:239:40
    |
239 |         fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                        ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:243:39
    |
243 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:249:40
    |
249 |         fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                        ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:253:39
    |
253 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:262:44
    |
262 |         fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                            ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:268:39
    |
268 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:274:44
    |
274 |         fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                            ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:280:39
    |
280 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:286:44
    |
286 |         fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                            ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:292:39
    |
292 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:304:32
    |
304 |         fn from(boxed: Box<dyn Future<Output = ()> + Send + 'a>) -> Self {
    |                                ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:316:36
    |
316 |         fn from(boxed: Pin<Box<dyn Future<Output = ()> + Send + 'a>>) -> Self {
    |                                    ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:328:32
    |
328 |         fn from(boxed: Box<dyn Future<Output = ()> + 'a>) -> Self {
    |                                ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:340:36
    |
340 |         fn from(boxed: Pin<Box<dyn Future<Output = ()> + 'a>>) -> Self {
    |                                    ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:3:18
  |
3 | use core::task::{RawWaker, RawWakerVTable, Waker};
  |                  ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:3:28
  |
3 | use core::task::{RawWaker, RawWakerVTable, Waker};
  |                            ^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:3:44
  |
3 | use core::task::{RawWaker, RawWakerVTable, Waker};
  |                                            ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:8:43
  |
8 | unsafe fn noop_clone(_data: *const ()) -> RawWaker {
  |                                           ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:14:26
   |
14 | const NOOP_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(noop_clone, noop, noop, noop);
   |                          ^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:14:43
   |
14 | const NOOP_WAKER_VTABLE: RawWakerVTable = RawWakerVTable::new(noop_clone, noop, noop, noop);
   |                                           ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:16:24
   |
16 | fn noop_raw_waker() -> RawWaker {
   |                        ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:17:5
   |
17 |     RawWaker::new(null(), &NOOP_WAKER_VTABLE)
   |     ^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:31:24
   |
31 | pub fn noop_waker() -> Waker {
   |                        ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:33:9
   |
33 |         Waker::from_raw(noop_raw_waker())
   |         ^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:49:37
   |
49 | pub fn noop_waker_ref() -> &'static Waker {
   |                                     ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/noop_waker.rs:51:48
   |
51 |         static NOOP_WAKER_INSTANCE: UnsafeCell<Waker> =
   |                                                ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:3:18
  |
3 | use core::task::{Waker, RawWaker, RawWakerVTable};
  |                  ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:3:25
  |
3 | use core::task::{Waker, RawWaker, RawWakerVTable};
  |                         ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:3:35
  |
3 | use core::task::{Waker, RawWaker, RawWakerVTable};
  |                                   ^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:6:54
  |
6 | pub(super) fn waker_vtable<W: ArcWake>() -> &'static RawWakerVTable {
  |                                                      ^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:7:6
  |
7 |     &RawWakerVTable::new(
  |      ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:19:34
   |
19 | pub fn waker<W>(wake: Arc<W>) -> Waker
   |                                  ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:26:9
   |
26 |         Waker::from_raw(RawWaker::new(ptr, waker_vtable::<W>()))
   |         ^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:26:25
   |
26 |         Waker::from_raw(RawWaker::new(ptr, waker_vtable::<W>()))
   |                         ^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:42:57
   |
42 | unsafe fn clone_arc_raw<T: ArcWake>(data: *const ()) -> RawWaker {
   |                                                         ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker.rs:44:5
   |
44 |     RawWaker::new(data, waker_vtable::<T>())
   |     ^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:7:18
  |
7 | use core::task::{Waker, RawWaker};
  |                  ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:7:25
  |
7 | use core::task::{Waker, RawWaker};
  |                         ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:67:9
   |
67 |         Waker::from_raw(RawWaker::new(ptr, waker_vtable::<W>()))
   |         ^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:67:25
   |
67 |         Waker::from_raw(RawWaker::new(ptr, waker_vtable::<W>()))
   |                         ^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:15:25
   |
15 |     waker: ManuallyDrop<Waker>,
   |                         ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:21:27
   |
21 |     pub fn new(waker: &'a Waker) -> Self {
   |                           ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:37:44
   |
37 |     pub fn new_unowned(waker: ManuallyDrop<Waker>) -> Self {
   |                                            ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:46:19
   |
46 |     type Target = Waker;
   |                   ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/waker_ref.rs:48:25
   |
48 |     fn deref(&self) -> &Waker {
   |                         ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:17:30
   |
17 |     future: *mut (dyn Future<Output = T> + 'static),
   |                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:18:41
   |
18 |     drop_fn: unsafe fn(*mut (dyn Future<Output = T> + 'static)),
   |                                         ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:30:25
   |
30 |     -> *mut (dyn Future<Output = T> + 'static)
   |                         ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:29:63
   |
29 | unsafe fn remove_future_lifetime<'a, T>(ptr: *mut (dyn Future<Output = T> + 'a))
   |                                                               ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:37:35
   |
37 |     -> unsafe fn(*mut (dyn Future<Output = T> + 'static))
   |                                   ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:36:72
   |
36 | unsafe fn remove_drop_lifetime<'a, T>(ptr: unsafe fn (*mut (dyn Future<Output = T> + 'a)))
   |                                                                        ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:183:15
    |
183 |     F: Future<Output = T> + Unpin + 'a
    |               ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:192:67
    |
192 | unsafe impl<'a, T> UnsafeFutureObj<'a, T> for &'a mut (dyn Future<Output = T> + Unpin + 'a)
    |                                                                   ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:203:15
    |
203 |     F: Future<Output = T> + 'a
    |               ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:212:71
    |
212 | unsafe impl<'a, T> UnsafeFutureObj<'a, T> for Pin<&'a mut (dyn Future<Output = T> + 'a)>
    |                                                                       ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:158:43
    |
158 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a);
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:178:42
    |
178 |     unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a));
    |                                          ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:185:43
    |
185 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:189:43
    |
189 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:194:43
    |
194 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:198:43
    |
198 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:205:43
    |
205 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:209:43
    |
209 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:214:43
    |
214 |     fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:218:43
    |
218 |     unsafe fn drop(_ptr: *mut (dyn Future<Output = T> + 'a)) {}
    |                                           ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:227:25
    |
227 |         where F: Future<Output = T> + 'a
    |                         ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:238:70
    |
238 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + 'a> {
    |                                                                      ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:248:70
    |
248 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Box<dyn Future<Output = T> + Send + 'a> {
    |                                                                      ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:260:19
    |
260 |         F: Future<Output = T> + 'a
    |                   ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:273:74
    |
273 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + 'a>> {
    |                                                                          ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:285:74
    |
285 |     unsafe impl<'a, T: 'a> UnsafeFutureObj<'a, T> for Pin<Box<dyn Future<Output = T> + Send + 'a>> {
    |                                                                          ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:297:24
    |
297 |     impl<'a, F: Future<Output = ()> + Send + 'a> From<Box<F>> for FutureObj<'a, ()> {
    |                        ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:303:34
    |
303 |     impl<'a> From<Box<dyn Future<Output = ()> + Send + 'a>> for FutureObj<'a, ()> {
    |                                  ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:309:24
    |
309 |     impl<'a, F: Future<Output = ()> + Send + 'a> From<Pin<Box<F>>> for FutureObj<'a, ()> {
    |                        ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:315:38
    |
315 |     impl<'a> From<Pin<Box<dyn Future<Output = ()> + Send + 'a>>> for FutureObj<'a, ()> {
    |                                      ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:321:24
    |
321 |     impl<'a, F: Future<Output = ()> + 'a> From<Box<F>> for LocalFutureObj<'a, ()> {
    |                        ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:327:34
    |
327 |     impl<'a> From<Box<dyn Future<Output = ()> + 'a>> for LocalFutureObj<'a, ()> {
    |                                  ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:333:24
    |
333 |     impl<'a, F: Future<Output = ()> + 'a> From<Pin<Box<F>>> for LocalFutureObj<'a, ()> {
    |                        ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:339:38
    |
339 |     impl<'a> From<Pin<Box<dyn Future<Output = ()> + 'a>>> for LocalFutureObj<'a, ()> {
    |                                      ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:229:47
    |
229 |         fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                               ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:233:46
    |
233 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:239:47
    |
239 |         fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                               ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:243:46
    |
243 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:249:47
    |
249 |         fn into_raw(self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                               ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:253:46
    |
253 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:262:51
    |
262 |         fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                                   ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:268:46
    |
268 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:274:51
    |
274 |         fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                                   ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:280:46
    |
280 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:286:51
    |
286 |         fn into_raw(mut self) -> *mut (dyn Future<Output = T> + 'a) {
    |                                                   ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:292:46
    |
292 |         unsafe fn drop(ptr: *mut (dyn Future<Output = T> + 'a)) {
    |                                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:304:39
    |
304 |         fn from(boxed: Box<dyn Future<Output = ()> + Send + 'a>) -> Self {
    |                                       ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:316:43
    |
316 |         fn from(boxed: Pin<Box<dyn Future<Output = ()> + Send + 'a>>) -> Self {
    |                                           ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:328:39
    |
328 |         fn from(boxed: Box<dyn Future<Output = ()> + 'a>) -> Self {
    |                                       ^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-task-0.3.1/src/future_obj.rs:340:43
    |
340 |         fn from(boxed: Pin<Box<dyn Future<Output = ()> + 'a>>) -> Self {
    |                                           ^^^^^^^^^^^

error: aborting due to 152 previous errors

Some errors occurred: E0432, E0658.
For more information about an error, try `rustc --explain E0432`.
error: Could not compile `futures-task`.
warning: build failed, waiting for other jobs to finish...
error[E0432]: unresolved import `core::task::Context`
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:5:18
  |
5 | use core::task::{Context, Poll};
  |                  ^^^^^^^ no `Context` in `task`

error[E0432]: unresolved import `core::task::Context`
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:5:18
  |
5 | use core::task::{Context, Poll};
  |                  ^^^^^^^ no `Context` in `task`

error[E0432]: unresolved import `core::task::Context`
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/mod.rs:9:22
  |
9 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
  |                      ^^^^^^^ no `Context` in `task`

error[E0658]: use of unstable library feature 'alloc': this library is unlikely to be stabilized in its current form or name (see issue #27783)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/lib.rs:20:1
   |
20 | extern crate alloc;
   | ^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/lib.rs:23:39
   |
23 | #[doc(hidden)] pub use self::future::{Future, FusedFuture, TryFuture};
   |                                       ^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:5:27
  |
5 | use core::task::{Context, Poll};
  |                           ^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:7:9
  |
7 | pub use core::future::Future;
  |         ^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:12:55
   |
12 | pub type BoxFuture<'a, T> = Pin<alloc::boxed::Box<dyn Future<Output = T> + Send + 'a>>;
   |                                                       ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:16:60
   |
16 | pub type LocalBoxFuture<'a, T> = Pin<alloc::boxed::Box<dyn Future<Output = T> + 'a>>;
   |                                                            ^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:26:24
   |
26 | pub trait FusedFuture: Future {
   |                        ^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:57:22
   |
57 | pub trait TryFuture: Future + private_try_future::Sealed {
   |                      ^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:76:23
   |
76 |     where F: ?Sized + Future<Output = Result<T, E>>
   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:72:10
   |
72 |     ) -> Poll<Result<Self::Ok, Self::Error>>;
   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:82:64
   |
82 |     fn try_poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<F::Output> {
   |                                                                ^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:48:9
   |
48 |     use super::Future;
   |         ^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:52:50
   |
52 |     impl<F, T, E> Sealed for F where F: ?Sized + Future<Output = Result<T, E>> {}
   |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:5:27
  |
5 | use core::task::{Context, Poll};
  |                           ^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:61:10
   |
61 |     ) -> Poll<Option<Self::Item>>;
   |          ^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:181:12
    |
181 |         -> Poll<Option<Result<Self::Ok, Self::Error>>>;
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:101:10
    |
101 |     ) -> Poll<Option<Self::Item>> {
    |          ^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:120:10
    |
120 |     ) -> Poll<Option<Self::Item>> {
    |          ^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:191:12
    |
191 |         -> Poll<Option<Result<Self::Ok, Self::Error>>>
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:208:14
    |
208 |         ) -> Poll<Option<Self::Item>> {
    |              ^^^^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/stream.rs:224:14
    |
224 |         ) -> Poll<Option<S::Item>> {
    |              ^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/mod.rs:9:31
  |
9 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
  |                               ^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/mod.rs:9:37
  |
9 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
  |                                     ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/mod.rs:9:44
  |
9 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
  |                                            ^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/mod.rs:9:54
  |
9 | pub use core::task::{Context, Poll, Waker, RawWaker, RawWakerVTable};
  |                                                      ^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
 --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/__internal/atomic_waker.rs:5:5
  |
5 | use core::task::Waker;
  |     ^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/__internal/atomic_waker.rs:91:30
   |
91 |     waker: UnsafeCell<Option<Waker>>,
   |                              ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/__internal/atomic_waker.rs:203:29
    |
203 |         impl AssertSync for Waker {}
    |                             ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/__internal/atomic_waker.rs:261:36
    |
261 |     pub fn register(&self, waker: &Waker) {
    |                                    ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
   --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/task/__internal/atomic_waker.rs:367:34
    |
367 |     pub fn take(&self) -> Option<Waker> {
    |                                  ^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:12:62
   |
12 | pub type BoxFuture<'a, T> = Pin<alloc::boxed::Box<dyn Future<Output = T> + Send + 'a>>;
   |                                                              ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:16:67
   |
16 | pub type LocalBoxFuture<'a, T> = Pin<alloc::boxed::Box<dyn Future<Output = T> + 'a>>;
   |                                                                   ^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:76:30
   |
76 |     where F: ?Sized + Future<Output = Result<T, E>>
   |                              ^^^^^^^^^^^^^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:82:69
   |
82 |     fn try_poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<F::Output> {
   |                                                                     ^^^^^^^^^

error[E0658]: use of unstable library feature 'futures_api': futures in libcore are unstable (see issue #50547)
  --> /home/cfenollosa/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-core-0.3.1/src/future.rs:52:57
   |
52 |     impl<F, T, E> Sealed for F where F: ?Sized + Future<Output = Result<T, E>> {}
   |                                                         ^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 38 previous errors

Some errors occurred: E0432, E0658.
For more information about an error, try `rustc --explain E0432`.
error: Could not compile `futures-core`.
warning: build failed, waiting for other jobs to finish...
error: build failed