DD build is broken after recent timely changes.

[ryzhyk]

It seems that a recent change to timely broke DD. Running cargo build in a fresh clone of the repo:

cargo build
warning: unused manifest key: source
   Compiling proc-macro2 v1.0.9
   Compiling unicode-xid v0.2.0
   Compiling syn v1.0.16
   Compiling serde v1.0.104
   Compiling unicode-width v0.1.7
   Compiling timely_bytes v0.11.0 (https://github.com/TimelyDataflow/timely-dataflow#6471f4bc)
   Compiling timely_logging v0.11.1 (https://github.com/TimelyDataflow/timely-dataflow#6471f4bc)
   Compiling abomonation v0.7.3
   Compiling fnv v1.0.6
   Compiling timely_sort v0.1.6
   Compiling getopts v0.2.21
   Compiling quote v1.0.3
   Compiling synstructure v0.12.3
   Compiling abomonation_derive v0.5.0
   Compiling serde_derive v1.0.104
^[[B   Compiling timely_communication v0.11.1 (https://github.com/TimelyDataflow/timely-dataflow#6471f4bc)
   Compiling timely v0.11.1 (https://github.com/TimelyDataflow/timely-dataflow#6471f4bc)
   Compiling differential-dataflow v0.11.0 (/home/lryzhyk/tmp/differential-dataflow)
error[E0308]: mismatched types
   --> src/operators/arrange/arrangement.rs:620:62
    |
620 | ...                   let batch = batcher.seal(upper.elements());
    |                                                ^^^^^^^^^^^^^^^^
    |                                                |
    |                                                expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                help: consider borrowing here: `&upper.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:489:116
    |
489 | ...                   let (mut source_cursor, source_storage): (T1::Cursor, _) = source_trace.cursor_through(lower_limit.elements()).expect("failed to acquire source cursor");
    |                                                                                                              ^^^^^^^^^^^^^^^^^^^^^^
    |                                                                                                              |
    |                                                                                                              expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                                                                              help: consider borrowing here: `&lower_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:491:117
    |
491 | ...                   let (mut output_cursor, output_storage): (T2::Cursor, _) = output_reader.cursor_through(lower_limit.elements()).expect("failed to acquire output cursor");
    |                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^
    |                                                                                                               |
    |                                                                                                               expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                                                                               help: consider borrowing here: `&lower_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:585:62
    |
585 | ...                   let batch = builder.done(output_lower.elements(), output_upper.elements(), &[G::Timestamp::minimum()]);
    |                                                ^^^^^^^^^^^^^^^^^^^^^^^
    |                                                |
    |                                                expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                help: consider borrowing here: `&output_lower.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:585:87
    |
585 | ...                   let batch = builder.done(output_lower.elements(), output_upper.elements(), &[G::Timestamp::minimum()]);
    |                                                                         ^^^^^^^^^^^^^^^^^^^^^^^
    |                                                                         |
    |                                                                         expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                                         help: consider borrowing here: `&output_upper.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:622:48
    |
622 | ...                   output_writer.seal(upper_limit.elements());
    |                                          ^^^^^^^^^^^^^^^^^^^^^^
    |                                          |
    |                                          expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                          help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:625:48
    |
625 | ...                   output_writer.seal(upper_limit.elements());
    |                                          ^^^^^^^^^^^^^^^^^^^^^^
    |                                          |
    |                                          expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                          help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:629:49
    |
629 |                         source_trace.advance_by(upper_limit.elements());
    |                                                 ^^^^^^^^^^^^^^^^^^^^^^
    |                                                 |
    |                                                 expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                 help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:630:50
    |
630 |                         output_reader.advance_by(upper_limit.elements());
    |                                                  ^^^^^^^^^^^^^^^^^^^^^^
    |                                                  |
    |                                                  expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                  help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:633:56
    |
633 |                         source_trace.distinguish_since(upper_limit.elements());
    |                                                        ^^^^^^^^^^^^^^^^^^^^^^
    |                                                        |
    |                                                        expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                        help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/reduce.rs:634:57
    |
634 |                         output_reader.distinguish_since(upper_limit.elements());
    |                                                         ^^^^^^^^^^^^^^^^^^^^^^
    |                                                         |
    |                                                         expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                         help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/join.rs:363:97
    |
363 | ...                   let (trace2_cursor, trace2_storage) = trace2.cursor_through(acknowledged2.elements()).unwrap();
    |                                                                                   ^^^^^^^^^^^^^^^^^^^^^^^^
    |                                                                                   |
    |                                                                                   expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                                                   help: consider borrowing here: `&acknowledged2.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/join.rs:399:97
    |
399 | ...                   let (trace1_cursor, trace1_storage) = trace1.cursor_through(acknowledged1.elements()).unwrap();
    |                                                                                   ^^^^^^^^^^^^^^^^^^^^^^^^
    |                                                                                   |
    |                                                                                   expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                                                   help: consider borrowing here: `&acknowledged1.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/join.rs:459:50
    |
459 |                         trace2.distinguish_since(acknowledged2.elements());
    |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^
    |                                                  |
    |                                                  expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                  help: consider borrowing here: `&acknowledged2.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/join.rs:473:50
    |
473 |                         trace1.distinguish_since(acknowledged1.elements());
    |                                                  ^^^^^^^^^^^^^^^^^^^^^^^^
    |                                                  |
    |                                                  expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                                  help: consider borrowing here: `&acknowledged1.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/count.rs:127:30
    |
127 |             trace.advance_by(upper_limit.elements());
    |                              ^^^^^^^^^^^^^^^^^^^^^^
    |                              |
    |                              expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                              help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/count.rs:128:37
    |
128 |             trace.distinguish_since(upper_limit.elements());
    |                                     ^^^^^^^^^^^^^^^^^^^^^^
    |                                     |
    |                                     expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                     help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/threshold.rs:190:34
    |
190 |                 trace.advance_by(upper_limit.elements());
    |                                  ^^^^^^^^^^^^^^^^^^^^^^
    |                                  |
    |                                  expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                  help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0308]: mismatched types
   --> src/operators/threshold.rs:191:41
    |
191 |                 trace.distinguish_since(upper_limit.elements());
    |                                         ^^^^^^^^^^^^^^^^^^^^^^
    |                                         |
    |                                         expected reference, found struct `timely::progress::frontier::AntichainRef`
    |                                         help: consider borrowing here: `&upper_limit.elements()`
    |
    = note: expected reference `&[<G as timely::dataflow::ScopeParent>::Timestamp]`
                  found struct `timely::progress::frontier::AntichainRef<'_, <G as timely::dataflow::ScopeParent>::Timestamp>`

error[E0277]: can't compare `&[<Self as trace::TraceReader>::Time]` with `timely::progress::frontier::AntichainRef<'_, <Self as trace::TraceReader>::Time>`
   --> src/trace/mod.rs:147:50
    |
147 |             if batch.is_empty() && batch.lower() == upper.elements() {
    |                                                  ^^ no implementation for `&[<Self as trace::TraceReader>::Time] == timely::progress::frontier::AntichainRef<'_, <Self as trace::TraceReader>::Time>`
    |
    = help: the trait `std::cmp::PartialEq<timely::progress::frontier::AntichainRef<'_, <Self as trace::TraceReader>::Time>>` is not implemented for `&[<Self as trace::TraceReader>::Time]`

error[E0308]: mismatched types
   --> src/trace/implementations/merge_batcher.rs:107:9
    |
107 |         self.frontier.elements()
    |         ^^^^^^^^^^^^^^^^^^^^^^^^
    |         |
    |         expected `&[T]`, found struct `timely::progress::frontier::AntichainRef`
    |         help: consider borrowing here: `&self.frontier.elements()`
    |
    = note: expected reference `&[T]`
                  found struct `timely::progress::frontier::AntichainRef<'_, T>`

error[E0308]: mismatched types
   --> src/trace/implementations/ord.rs:230:27
    |
230 |             since = antichain_join(since.elements(), compaction_frontier);
    |                                    ^^^^^^^^^^^^^^^^
    |                                    |
    |                                    expected `&[T]`, found struct `timely::progress::frontier::AntichainRef`
    |                                    help: consider borrowing here: `&since.elements()`
    |
    = note: expected reference `&[T]`
                  found struct `timely::progress::frontier::AntichainRef<'_, T>`

error[E0308]: mismatched types
   --> src/trace/implementations/ord.rs:233:70
    |
233 |         let description = Description::new(batch1.lower(), batch2.upper(), since.elements());
    |                                                                            ^^^^^^^^^^^^^^^^
    |                                                                            |
    |                                                                            expected `&[T]`, found struct `timely::progress::frontier::AntichainRef`
    |                                                                            help: consider borrowing here: `&since.elements()`
    |
    = note: expected reference `&[T]`
                  found struct `timely::progress::frontier::AntichainRef<'_, T>`

error[E0308]: mismatched types
   --> src/trace/implementations/ord.rs:549:27
    |
549 |             since = antichain_join(since.elements(), compaction_frontier);
    |                                    ^^^^^^^^^^^^^^^^
    |                                    |
    |                                    expected `&[T]`, found struct `timely::progress::frontier::AntichainRef`
    |                                    help: consider borrowing here: `&since.elements()`
    |
    = note: expected reference `&[T]`
                  found struct `timely::progress::frontier::AntichainRef<'_, T>`

error[E0308]: mismatched types
   --> src/trace/implementations/ord.rs:552:70
    |
552 |         let description = Description::new(batch1.lower(), batch2.upper(), since.elements());
    |                                                                            ^^^^^^^^^^^^^^^^
    |                                                                            |
    |                                                                            expected `&[T]`, found struct `timely::progress::frontier::AntichainRef`
    |                                                                            help: consider borrowing here: `&since.elements()`
    |
    = note: expected reference `&[T]`
                  found struct `timely::progress::frontier::AntichainRef<'_, T>`

error: aborting due to 25 previous errors

Some errors have detailed explanations: E0277, E0308.
For more information about an error, try `rustc --explain E0277`.
error: could not compile `differential-dataflow`.

[frankmcsherry]

Whoops. That was unintentional. There is a corresponding fix up in a PR for differential (#259) but the plan wasn't to break things before then. There is a pretty easy local fix, or we could decide to land the PR (which breaks some other external APIs but is at least internally consistent).

[frankmcsherry]

Let me check out a timely fix that could simplify things for the moment (introducing a parallel method to elements() that better lines up some APIs).

[frankmcsherry]

Timely master should be fixed, unless I screwed things up again. The PR will break instead.

[ryzhyk]

Thanks!

[antiguru]

Not a problem anymore.