diff --git a/ethers-core/src/utils/anvil.rs b/ethers-core/src/utils/anvil.rs
index 26612aac..1fe5baf7 100644
--- a/ethers-core/src/utils/anvil.rs
+++ b/ethers-core/src/utils/anvil.rs
@@ -85,6 +85,7 @@ impl Drop for AnvilInstance {
 /// drop(anvil); // this will kill the instance
 /// ```
 #[derive(Debug, Clone, Default)]
+#[must_use = "This Builder struct does nothing unless it is `spawn`ed"]
 pub struct Anvil {
     program: Option<PathBuf>,
     port: Option<u16>,
@@ -135,35 +136,30 @@ impl Anvil {
     ///
     /// By default, it's expected that `anvil` is in `$PATH`, see also
     /// [`std::process::Command::new()`]
-    #[must_use]
     pub fn path<T: Into<PathBuf>>(mut self, path: T) -> Self {
         self.program = Some(path.into());
         self
     }
 
     /// Sets the port which will be used when the `anvil` instance is launched.
-    #[must_use]
     pub fn port<T: Into<u16>>(mut self, port: T) -> Self {
         self.port = Some(port.into());
         self
     }
 
     /// Sets the chain_id the `anvil` instance will use.
-    #[must_use]
     pub fn chain_id<T: Into<u64>>(mut self, chain_id: T) -> Self {
         self.chain_id = Some(chain_id.into());
         self
     }
 
     /// Sets the mnemonic which will be used when the `anvil` instance is launched.
-    #[must_use]
     pub fn mnemonic<T: Into<String>>(mut self, mnemonic: T) -> Self {
         self.mnemonic = Some(mnemonic.into());
         self
     }
 
     /// Sets the block-time in seconds which will be used when the `anvil` instance is launched.
-    #[must_use]
     pub fn block_time<T: Into<u64>>(mut self, block_time: T) -> Self {
         self.block_time = Some(block_time.into());
         self
@@ -172,7 +168,6 @@ impl Anvil {
     /// Sets the `fork-block-number` which will be used in addition to [`Self::fork`].
     ///
     /// **Note:** if set, then this requires `fork` to be set as well
-    #[must_use]
     pub fn fork_block_number<T: Into<u64>>(mut self, fork_block_number: T) -> Self {
         self.fork_block_number = Some(fork_block_number.into());
         self
@@ -182,21 +177,18 @@ impl Anvil {
     /// at a given block. Input should be the HTTP location and port of the other client,
     /// e.g. `http://localhost:8545`. You can optionally specify the block to fork from
     /// using an @ sign: `http://localhost:8545@1599200`
-    #[must_use]
     pub fn fork<T: Into<String>>(mut self, fork: T) -> Self {
         self.fork = Some(fork.into());
         self
     }
 
     /// Adds an argument to pass to the `anvil`.
-    #[must_use]
     pub fn arg<T: Into<String>>(mut self, arg: T) -> Self {
         self.args.push(arg.into());
         self
     }
 
     /// Adds multiple arguments to pass to the `anvil`.
-    #[must_use]
     pub fn args<I, S>(mut self, args: I) -> Self
     where
         I: IntoIterator<Item = S>,
@@ -209,14 +201,17 @@ impl Anvil {
     }
 
     /// Sets the timeout which will be used when the `anvil` instance is launched.
-    #[must_use]
     pub fn timeout<T: Into<u64>>(mut self, timeout: T) -> Self {
         self.timeout = Some(timeout.into());
         self
     }
 
-    /// Consumes the builder and spawns `anvil` with stdout redirected
-    /// to /dev/null.
+    /// Consumes the builder and spawns `anvil`.
+    ///
+    /// # Panics
+    ///
+    /// If spawning the instance fails at any point.
+    #[track_caller]
     pub fn spawn(self) -> AnvilInstance {
         let mut cmd = if let Some(ref prg) = self.program {
             Command::new(prg)
diff --git a/ethers-core/src/utils/ganache.rs b/ethers-core/src/utils/ganache.rs
index d1300e78..d040eb73 100644
--- a/ethers-core/src/utils/ganache.rs
+++ b/ethers-core/src/utils/ganache.rs
@@ -78,6 +78,7 @@ impl Drop for GanacheInstance {
 /// drop(ganache); // this will kill the instance
 /// ```
 #[derive(Clone, Default)]
+#[must_use = "This Builder struct does nothing unless it is `spawn`ed"]
 pub struct Ganache {
     port: Option<u16>,
     block_time: Option<u64>,
@@ -102,21 +103,18 @@ impl Ganache {
     }
 
     /// Sets the port which will be used when the `ganache-cli` instance is launched.
-    #[must_use]
     pub fn port<T: Into<u16>>(mut self, port: T) -> Self {
         self.port = Some(port.into());
         self
     }
 
     /// Sets the mnemonic which will be used when the `ganache-cli` instance is launched.
-    #[must_use]
     pub fn mnemonic<T: Into<String>>(mut self, mnemonic: T) -> Self {
         self.mnemonic = Some(mnemonic.into());
         self
     }
 
     /// Sets the block-time which will be used when the `ganache-cli` instance is launched.
-    #[must_use]
     pub fn block_time<T: Into<u64>>(mut self, block_time: T) -> Self {
         self.block_time = Some(block_time.into());
         self
@@ -126,21 +124,18 @@ impl Ganache {
     /// at a given block. Input should be the HTTP location and port of the other client,
     /// e.g. `http://localhost:8545`. You can optionally specify the block to fork from
     /// using an @ sign: `http://localhost:8545@1599200`
-    #[must_use]
     pub fn fork<T: Into<String>>(mut self, fork: T) -> Self {
         self.fork = Some(fork.into());
         self
     }
 
     /// Adds an argument to pass to the `ganache-cli`.
-    #[must_use]
     pub fn arg<T: Into<String>>(mut self, arg: T) -> Self {
         self.args.push(arg.into());
         self
     }
 
     /// Adds multiple arguments to pass to the `ganache-cli`.
-    #[must_use]
     pub fn args<I, S>(mut self, args: I) -> Self
     where
         I: IntoIterator<Item = S>,
@@ -152,9 +147,12 @@ impl Ganache {
         self
     }
 
-    /// Consumes the builder and spawns `ganache-cli` with stdout redirected
-    /// to /dev/null. This takes ~2 seconds to execute as it blocks while
-    /// waiting for `ganache-cli` to launch.
+    /// Consumes the builder and spawns `ganache-cli`.
+    ///
+    /// # Panics
+    ///
+    /// If spawning the instance fails at any point.
+    #[track_caller]
     pub fn spawn(self) -> GanacheInstance {
         let mut cmd = Command::new("ganache-cli");
         cmd.stdout(std::process::Stdio::piped());
diff --git a/ethers-core/src/utils/geth.rs b/ethers-core/src/utils/geth.rs
index bf9b0b2b..4cb6a1d7 100644
--- a/ethers-core/src/utils/geth.rs
+++ b/ethers-core/src/utils/geth.rs
@@ -189,6 +189,7 @@ impl Default for PrivateNetOptions {
 /// drop(geth); // this will kill the instance
 /// ```
 #[derive(Clone, Default)]
+#[must_use = "This Builder struct does nothing unless it is `spawn`ed"]
 pub struct Geth {
     program: Option<PathBuf>,
     port: Option<u16>,
@@ -234,7 +235,6 @@ impl Geth {
     ///
     /// By default, it's expected that `geth` is in `$PATH`, see also
     /// [`std::process::Command::new()`]
-    #[must_use]
     pub fn path<T: Into<PathBuf>>(mut self, path: T) -> Self {
         self.program = Some(path.into());
         self
@@ -245,14 +245,12 @@ impl Geth {
     ///
     /// The address derived from this private key will be used to set the `miner.etherbase` field
     /// on the node.
-    #[must_use]
     pub fn set_clique_private_key<T: Into<SigningKey>>(mut self, private_key: T) -> Self {
         self.clique_private_key = Some(private_key.into());
         self
     }
 
     /// Sets the port which will be used when the `geth-cli` instance is launched.
-    #[must_use]
     pub fn port<T: Into<u16>>(mut self, port: T) -> Self {
         self.port = Some(port.into());
         self
@@ -262,7 +260,6 @@ impl Geth {
     ///
     /// This will put the geth instance into non-dev mode, discarding any previously set dev-mode
     /// options.
-    #[must_use]
     pub fn p2p_port(mut self, port: u16) -> Self {
         match self.mode {
             GethMode::Dev(_) => {
@@ -280,21 +277,18 @@ impl Geth {
     ///
     /// This will put the geth instance in `dev` mode, discarding any previously set options that
     /// cannot be used in dev mode.
-    #[must_use]
     pub fn block_time<T: Into<u64>>(mut self, block_time: T) -> Self {
         self.mode = GethMode::Dev(DevOptions { block_time: Some(block_time.into()) });
         self
     }
 
     /// Sets the chain id for the geth instance.
-    #[must_use]
     pub fn chain_id<T: Into<u64>>(mut self, chain_id: T) -> Self {
         self.chain_id = Some(chain_id.into());
         self
     }
 
     /// Allow geth to unlock accounts when rpc apis are open.
-    #[must_use]
     pub fn insecure_unlock(mut self) -> Self {
         self.insecure_unlock = true;
         self
@@ -304,7 +298,6 @@ impl Geth {
     ///
     /// This will put the geth instance into non-dev mode, discarding any previously set dev-mode
     /// options.
-    #[must_use]
     pub fn disable_discovery(mut self) -> Self {
         self.inner_disable_discovery();
         self
@@ -321,14 +314,12 @@ impl Geth {
     }
 
     /// Manually sets the IPC path for the socket manually.
-    #[must_use]
     pub fn ipc_path<T: Into<PathBuf>>(mut self, path: T) -> Self {
         self.ipc_path = Some(path.into());
         self
     }
 
     /// Sets the data directory for geth.
-    #[must_use]
     pub fn data_dir<T: Into<PathBuf>>(mut self, path: T) -> Self {
         self.data_dir = Some(path.into());
         self
@@ -340,21 +331,22 @@ impl Geth {
     /// set to the same value as `data_dir`.
     ///
     /// This is destructive and will overwrite any existing data in the data directory.
-    #[must_use]
     pub fn genesis(mut self, genesis: Genesis) -> Self {
         self.genesis = Some(genesis);
         self
     }
 
     /// Sets the port for authenticated RPC connections.
-    #[must_use]
     pub fn authrpc_port(mut self, port: u16) -> Self {
         self.authrpc_port = Some(port);
         self
     }
 
-    /// Consumes the builder and spawns `geth` with stdout redirected to /dev/null.
-    #[must_use]
+    /// Consumes the builder and spawns `geth`.
+    ///
+    /// # Panics
+    ///
+    /// If spawning the instance fails at any point.
     #[track_caller]
     pub fn spawn(mut self) -> GethInstance {
         let bin_path = match self.program.as_ref() {
diff --git a/ethers/tests/eip712.rs b/ethers/tests/eip712.rs
index d50e94b1..4cc16063 100644
--- a/ethers/tests/eip712.rs
+++ b/ethers/tests/eip712.rs
@@ -42,7 +42,6 @@ async fn test_derive_eip712() {
     const PATH: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/tests/DeriveEip712Test.sol");
     Solc::find_or_install_svm_version("0.6.0").unwrap(); // install solc
     let result = Solc::default().compile_source(PATH).unwrap();
-    eprintln!("{result:#?}");
     let (abi, bytecode, _) = result
         .find("DeriveEip712Test")
         .expect("failed to get DeriveEip712Test contract")