Update the rust-starter template to match new API (risc0#519)

* Update the rust-starter template to match new API

* Incorporate testing the template within CI

.github/workflows/main.yml

@@ -100,3 +100,19 @@ jobs:
       - uses: ./.github/actions/rustup
       - uses: ./.github/actions/sccache
       - run: RISC0_SKIP_BUILD=1 cargo doc --no-deps --exclude=risc0-zkvm-methods --workspace
+
+  check_template:
+    runs-on: [self-hosted, prod, cpu, "${{ matrix.os }}"]
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [Linux, macOS]
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ./.github/actions/rustup
+      - run: |
+          cargo run -p cargo-risczero risczero new --template templates/rust-starter --templ-subdir="" --path $(pwd) --dest ${{ runner.temp }} template-test
+        shell: bash
+      - run: cargo build --release --manifest-path ${{ runner.temp }}/template-test/Cargo.toml
+      - run: ${{ runner.temp }}/template-test/target/release/host

templates/rust-starter/host/src/main.rs

@@ -2,7 +2,7 @@
 // is `multiply`, replace `METHOD_NAME_ELF` with `MULTIPLY_ELF` and replace
 // `METHOD_NAME_ID` with `MULTIPLY_ID`
 use methods::{METHOD_NAME_ELF, METHOD_NAME_ID};
-use risc0_zkvm::ExecutorEnv;
+use risc0_zkvm::{prove::default_hal, Executor, ExecutorEnv};
 // TODO: Uncomment the `use` line below for serialization helper functions for
 // communication with the guest
 // use risc0_zkvm::serde::{from_slice, to_vec}
@@ -11,7 +11,8 @@ fn main() {
     let env = ExecutorEnv::default();
     let mut exec = Executor::from_elf(env, METHOD_NAME_ELF).unwrap();
     let session = exec.run().unwrap();
-    let receipt = session.prove().unwrap();
+    let (hal, eval) = default_hal();
+    let receipt = session.prove(hal.as_ref(), &eval).unwrap();
 
     // TODO: Implement code for transmitting or serializing the receipt for
     // other parties to verify here