fix: Download expected bb version if installed backend has version mismatch

tooling/backend_interface/src/cli/mod.rs

@@ -6,13 +6,15 @@ mod info;
 mod prove;
 mod verify;
 mod write_vk;
+mod version;
 
 pub(crate) use contract::ContractCommand;
 pub(crate) use gates::GatesCommand;
 pub(crate) use info::InfoCommand;
 pub(crate) use prove::ProveCommand;
 pub(crate) use verify::VerifyCommand;
 pub(crate) use write_vk::WriteVkCommand;
+pub(crate) use version::VersionCommand;
 
 #[test]
 fn no_command_provided_works() -> Result<(), crate::BackendError> {

tooling/backend_interface/src/cli/version.rs

@@ -0,0 +1,28 @@
+use std::path::Path;
+
+use crate::BackendError;
+
+use super::string_from_stderr;
+
+/// VersionCommand will call the backend binary
+/// to query installed version.
+pub(crate) struct VersionCommand {}
+
+impl VersionCommand {
+    pub(crate) fn run(self, binary_path: &Path) -> Result<String, BackendError> {
+        let mut command = std::process::Command::new(binary_path);
+
+        command
+            .arg("--version");
+
+        let output = command.output()?;
+        if output.status.success() {
+            match String::from_utf8(output.stdout) {
+                Ok(result) => Ok(result),
+                Err(_) => Err(BackendError::CommandFailed("Unexpected output from --version check.".to_owned())),
+            }
+        } else {
+            Err(BackendError::CommandFailed(string_from_stderr(&output.stderr)))
+        }
+    }
+}

tooling/backend_interface/src/lib.rs

@@ -10,6 +10,8 @@ mod smart_contract;
 
 use acvm::acir::circuit::Opcode;
 use bb_abstraction_leaks::ACVM_BACKEND_BARRETENBERG;
+use bb_abstraction_leaks::BB_VERSION;
+use cli::VersionCommand;
 pub use download::download_backend;
 
 const BACKENDS_DIR: &str = ".nargo/backends";
@@ -104,6 +106,15 @@ impl Backend {
     fn crs_directory(&self) -> PathBuf {
         self.backend_directory().join("crs")
     }
+
+    fn assert_correct_version(&self) -> Result<String, BackendError> {
+        let binary_path = self.binary_path();
+        let version_string = VersionCommand{}.run(binary_path)?;
+        if version_string.as_str() != BB_VERSION {
+            println!("WARNING!: Configured backend version `{:}` is different from expected `{:}`", version_string, BB_VERSION);
+        }
+        Ok(version_string)
+    }
 }
 
 pub struct BackendOpcodeSupport {

tooling/backend_interface/src/proof_system.rs

@@ -39,6 +39,8 @@ impl Backend {
     ) -> Result<Vec<u8>, BackendError> {
         let binary_path = self.assert_binary_exists()?;
 
+        self.assert_correct_version()?;
+
         let temp_directory = tempdir().expect("could not create a temporary directory");
         let temp_directory = temp_directory.path().to_path_buf();
 
@@ -78,6 +80,7 @@ impl Backend {
         is_recursive: bool,
     ) -> Result<bool, BackendError> {
         let binary_path = self.assert_binary_exists()?;
+        self.assert_correct_version()?;
 
         let temp_directory = tempdir().expect("could not create a temporary directory");
         let temp_directory = temp_directory.path().to_path_buf();

tooling/backend_interface/src/smart_contract.rs

@@ -10,6 +10,8 @@ impl Backend {
     pub fn eth_contract(&self, circuit: &Circuit) -> Result<String, BackendError> {
         let binary_path = self.assert_binary_exists()?;
 
+        self.assert_correct_version()?;
+
         let temp_directory = tempdir().expect("could not create a temporary directory");
         let temp_directory_path = temp_directory.path().to_path_buf();
 

tooling/bb_abstraction_leaks/build.rs

@@ -35,6 +35,7 @@ fn main() -> Result<(), String> {
     };
 
     println!("cargo:rustc-env=BB_BINARY_URL={}", get_bb_download_url(arch, os));
+    println!("cargo:rustc-env=BB_VERSION={}", VERSION);
 
     Ok(())
 }

tooling/bb_abstraction_leaks/src/lib.rs

@@ -5,6 +5,7 @@ use acvm::FieldElement;
 
 pub const ACVM_BACKEND_BARRETENBERG: &str = "acvm-backend-barretenberg";
 pub const BB_DOWNLOAD_URL: &str = env!("BB_BINARY_URL");
+pub const BB_VERSION: &str = env!("BB_VERSION");
 
 /// Embed the Solidity verifier file
 const ULTRA_VERIFIER_CONTRACT: &str = include_str!("contract.sol");