Update nightly version to avoid issue with transitive dependency.

Author: sjudson

cli/src/command/host.rs

@@ -133,11 +133,11 @@ fn setup_crate(host_path: PathBuf, rev: Option<String>, tag: Option<String>) ->
         GUEST_TEMPLATE_CARGO_CONFIG,
     )?;
 
-    // guest/src/main.rs
-    fs::write(guest_path.join("src/main.rs"), GUEST_TEMPLATE_SRC_MAIN)?;
-    fs::write(guest_path.join("rust-toolchain.toml"), RUST_TOOLCHAIN)?;
+// guest/src/main.rs
+fs::write(guest_path.join("src/main.rs"), GUEST_TEMPLATE_SRC_MAIN)?;
+fs::write(guest_path.join("rust-toolchain.toml"), RUST_TOOLCHAIN)?;
 
-    Ok(())
+Ok(())
 }
 
 macro_rules! host_examples_dir {
@@ -164,5 +164,5 @@ const GUEST_TEMPLATE_SRC_MAIN: &str = include_str!(concat!(guest_examples_dir!()
 
 // freeze toolchain that works with all provers
 const RUST_TOOLCHAIN: &str = r#"[toolchain]
-channel = "nightly-2025-04-06"
+channel = "nightly-2025-05-09"
 "#;

rust-toolchain.toml

@@ -1,2 +1,2 @@
 [toolchain]
-channel = "nightly-2025-04-06"
+channel = "nightly-2025-05-09"

sdk/README.md

@@ -17,13 +17,13 @@ $ rustup target add riscv32im-unknown-none-elf
 Then, install the Nexus zkVM:
 
 ```shell
-$ rustup run nightly-2025-04-06 cargo install --git https://github.com/nexus-xyz/nexus-zkvm cargo-nexus --tag 'v0.3.5'
+$ rustup run nightly-2025-05-09 cargo install --git https://github.com/nexus-xyz/nexus-zkvm cargo-nexus --tag 'v0.3.5'
 ```
 
 And verify the installation:
 
 ```shell
-$ rustup run nightly-2025-04-06 cargo nexus --help
+$ rustup run nightly-2025-05-09 cargo nexus --help
 ```
 
 This should print the available CLI commands. At present, the `cargo nexus` CLI is minimal, providing just a `cargo nexus host` command to setup an SDK based project.
@@ -33,7 +33,7 @@ This should print the available CLI commands. At present, the `cargo nexus` CLI
 To use the zkVM programmatically, we need two programs: a _guest_ program that runs on the zkVM, and a _host_ program that operates the zkVM itself. Run:
 
 ```shell
-$ rustup run nightly-2025-04-06 cargo nexus host nexus-host
+$ rustup run nightly-2025-05-09 cargo nexus host nexus-host
 ```
 
 This will create a new Rust project directory with the following structure: