Fix genesis state download panic when running in debug mode (#4753)

## Issue Addressed

#4738 

## Proposed Changes

See the above issue for details. Went with option #2 to use the async reqwest client in `Eth2NetworkConfig` and propagate the async-ness.

boot_node/src/config.rs

@@ -25,7 +25,7 @@ pub struct BootNodeConfig<T: EthSpec> {
 }
 
 impl<T: EthSpec> BootNodeConfig<T> {
-    pub fn new(
+    pub async fn new(
         matches: &ArgMatches<'_>,
         eth2_network_config: &Eth2NetworkConfig,
     ) -> Result<Self, String> {
@@ -99,7 +99,7 @@ impl<T: EthSpec> BootNodeConfig<T> {
 
                 if eth2_network_config.genesis_state_is_known() {
                     let genesis_state = eth2_network_config
-                        .genesis_state::<T>(genesis_state_url.as_deref(), genesis_state_url_timeout, &logger)?
+                        .genesis_state::<T>(genesis_state_url.as_deref(), genesis_state_url_timeout, &logger).await?
                         .ok_or_else(|| {
                             "The genesis state for this network is not known, this is an unsupported mode"
                                 .to_string()

boot_node/src/lib.rs

@@ -7,7 +7,7 @@ mod cli;
 pub mod config;
 mod server;
 pub use cli::cli_app;
-use config::{BootNodeConfig, BootNodeConfigSerialization};
+use config::BootNodeConfig;
 use types::{EthSpec, EthSpecId};
 
 const LOG_CHANNEL_SIZE: usize = 2048;
@@ -81,20 +81,13 @@ fn main<T: EthSpec>(
         .build()
         .map_err(|e| format!("Failed to build runtime: {}", e))?;
 
-    // parse the CLI args into a useable config
-    let config: BootNodeConfig<T> = BootNodeConfig::new(bn_matches, eth2_network_config)?;
-
-    // Dump configs if `dump-config` or `dump-chain-config` flags are set
-    let config_sz = BootNodeConfigSerialization::from_config_ref(&config);
-    clap_utils::check_dump_configs::<_, T>(
-        lh_matches,
-        &config_sz,
-        &eth2_network_config.chain_spec::<T>()?,
-    )?;
-
     // Run the boot node
-    if !lh_matches.is_present("immediate-shutdown") {
-        runtime.block_on(server::run(config, log));
-    }
+    runtime.block_on(server::run::<T>(
+        lh_matches,
+        bn_matches,
+        eth2_network_config,
+        log,
+    ))?;
+
     Ok(())
 }

boot_node/src/server.rs

@@ -1,6 +1,9 @@
 //! The main bootnode server execution.
 
 use super::BootNodeConfig;
+use crate::config::BootNodeConfigSerialization;
+use clap::ArgMatches;
+use eth2_network_config::Eth2NetworkConfig;
 use lighthouse_network::{
     discv5::{enr::NodeId, Discv5, Discv5Event},
     EnrExt, Eth2Enr,
@@ -8,7 +11,27 @@ use lighthouse_network::{
 use slog::info;
 use types::EthSpec;
 
-pub async fn run<T: EthSpec>(config: BootNodeConfig<T>, log: slog::Logger) {
+pub async fn run<T: EthSpec>(
+    lh_matches: &ArgMatches<'_>,
+    bn_matches: &ArgMatches<'_>,
+    eth2_network_config: &Eth2NetworkConfig,
+    log: slog::Logger,
+) -> Result<(), String> {
+    // parse the CLI args into a useable config
+    let config: BootNodeConfig<T> = BootNodeConfig::new(bn_matches, eth2_network_config).await?;
+
+    // Dump configs if `dump-config` or `dump-chain-config` flags are set
+    let config_sz = BootNodeConfigSerialization::from_config_ref(&config);
+    clap_utils::check_dump_configs::<_, T>(
+        lh_matches,
+        &config_sz,
+        &eth2_network_config.chain_spec::<T>()?,
+    )?;
+
+    if lh_matches.is_present("immediate-shutdown") {
+        return Ok(());
+    }
+
     let BootNodeConfig {
         boot_nodes,
         local_enr,
@@ -65,8 +88,7 @@ pub async fn run<T: EthSpec>(config: BootNodeConfig<T>, log: slog::Logger) {
 
     // start the server
     if let Err(e) = discv5.start().await {
-        slog::crit!(log, "Could not start discv5 server"; "error" => %e);
-        return;
+        return Err(format!("Could not start discv5 server: {e:?}"));
     }
 
     // if there are peers in the local routing table, establish a session by running a query
@@ -82,8 +104,7 @@ pub async fn run<T: EthSpec>(config: BootNodeConfig<T>, log: slog::Logger) {
     let mut event_stream = match discv5.event_stream().await {
         Ok(stream) => stream,
         Err(e) => {
-            slog::crit!(log, "Failed to obtain event stream"; "error" => %e);
-            return;
+            return Err(format!("Failed to obtain event stream: {e:?}"));
         }
     };