在substrate.dev墨迹中构建失败！教程。sp-是否缺少类型？

Question

我的构建失败了。

在我用命令测试我的契约之前，一切看起来都很好：

cargo +nightly test

我收到错误E0282

下面是完整的错误报告：

error[E0282]: type annotations needed
      --> /home/mal/.cargo/registry/src/github.com-1ecc6299db9ec823/sp-arithmetic-2.0.0/src/fixed_point.rs:541:9
       |
  541  |                   let accuracy = P::ACCURACY.saturated_into();
       |                       ^^^^^^^^ consider giving `accuracy` a type
  ...
  1595 | / implement_fixed!(
  1596 | |     FixedI64,
  1597 | |     test_fixed_i64,
  1598 | |     i64,
  ...    |
  1601 | |     "_Fixed Point 64 bits signed, range = [-9223372036.854775808, 9223372036.854775807]_",
  1602 | | );
       | |__- in this macro invocation
       |
       = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

  error[E0282]: type annotations needed
      --> /home/mal/.cargo/registry/src/github.com-1ecc6299db9ec823/sp-arithmetic-2.0.0/src/fixed_point.rs:541:9
       |
  541  |                   let accuracy = P::ACCURACY.saturated_into();
       |                       ^^^^^^^^ consider giving `accuracy` a type
  ...
  1604 | / implement_fixed!(
  1605 | |     FixedI128,
  1606 | |     test_fixed_i128,
  1607 | |     i128,
  ...    |
  1611 | |         [-170141183460469231731.687303715884105728, 170141183460469231731.687303715884105727]_",
  1612 | | );
       | |__- in this macro invocation
       |
       = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

  error[E0282]: type annotations needed
      --> /home/mal/.cargo/registry/src/github.com-1ecc6299db9ec823/sp-arithmetic-2.0.0/src/fixed_point.rs:541:9
       |
  541  |                   let accuracy = P::ACCURACY.saturated_into();
       |                       ^^^^^^^^ consider giving `accuracy` a type
  ...
  1614 | / implement_fixed!(
  1615 | |     FixedU128,
  1616 | |     test_fixed_u128,
  1617 | |     u128,
  ...    |
  1621 | |         [0.000000000000000000, 340282366920938463463.374607431768211455]_",
  1622 | | );
       | |__- in this macro invocation
       |
       = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

  error: aborting due to 3 previous errors

  For more information about this error, try `rustc --explain E0282`.
  error: could not compile `sp-arithmetic`

这是一个更广泛的教程的一部分。

我相信rust已经更新了。

问题似乎出在宏算法上，但是我不确定如何给它一个“类型”。我的铁锈是不存在的。

非常渴望进入Ink！因此，任何帮助都是非常感谢的。

Answer 1

该错误的原因是从版本2020-10-06开始的rust nightly编译器中的regression。在这个问题得到解决之前，你需要使用rustup toolchain install 2020-10-05来构建你的运行时。通常，最新的每晚都会自动用于构建您的运行时。您可以通过设置WASM_BUILD_TOOLCHAIN环境变量来覆盖此行为。在这种情况下：

export WASM_BUILD_TOOLCHAIN='nightly-2020-10-05'

在使用货物合同建立合同的情况下，您应该使用：

cargo +nightly-2020-10-05 contract build