title: Node Template build errors
body: <p>Followed steps from this link <a href="https://substrate.dev/docs/en/tutorials/create-your-first-substrate-chain/setup" rel="nofollow noreferrer">https://substrate.dev/docs/en/tutorials/create-your-first-substrate-chain/setup</a></p>
  <p>but getting errors after &gt;cargo build --release</p>
  <p>error[E0277]: the trait bound <code>&lt;System as Trait&gt;::BlockNumber: From&lt;i32&gt;</code> is not satisfied
  --&gt; /Users/ion/.cargo/registry/src/github.com-1ecc6299db9ec823/frame-executive-2.0.0/src/lib.rs:471:37
  |
  471 |             header.number().saturating_sub(1.into())
  |                                              ^^^^ the trait <code>From&lt;i32&gt;</code> is not implemented for <code>&lt;System as Trait&gt;::BlockNumber</code>
  |
  = note: required because of the requirements on the impl of <code>Into&lt;&lt;System as Trait&gt;::BlockNumber&gt;</code> for <code>i32</code>
  help: consider further restricting the associated type
  |
  449 |     pub fn offchain_worker(header: &amp;System::Header) where ::BlockNumber: From {</p>
  <p>Actually, there were 2 other couple errors, but I managed to get past those. Any tips on how to resolve this?</p>