From 39744df93f0ba67880f95c0ac75ac4e7a5a5ae62 Mon Sep 17 00:00:00 2001
From: Akihito Nakano <sora.akatsuki@gmail.com>
Date: Fri, 30 May 2025 12:05:37 +0900
Subject: [PATCH] simulator: Fix `Failed to initialize dependency logging`
 (#7393)

The simulator works but always emits the following message:

```
$ cargo run --release --bin simulator basic-sim
...
...
Failed to initialize dependency logging: attempted to set a logger after the logging system was already initialized
...
...
```


  This PR removes the initialization with `env_logger`.

(Update)
With https://github.com/sigp/lighthouse/pull/7433 merged, the libp2p/discv5 logs are saved in separate files and respect the `RUST_LOG` env var for log level configuration.
---
 Cargo.lock                    | 2 --
 testing/simulator/Cargo.toml  | 2 --
 testing/simulator/src/main.rs | 4 ----
 3 files changed, 8 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1b506f6212..327908027c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -8469,9 +8469,7 @@ name = "simulator"
 version = "0.2.0"
 dependencies = [
  "clap",
- "env_logger 0.9.3",
  "environment",
- "eth2_network_config",
  "execution_layer",
  "futures",
  "kzg",
diff --git a/testing/simulator/Cargo.toml b/testing/simulator/Cargo.toml
index cf0d03c24f..cd23138a1c 100644
--- a/testing/simulator/Cargo.toml
+++ b/testing/simulator/Cargo.toml
@@ -7,9 +7,7 @@ edition = { workspace = true }
 
 [dependencies]
 clap = { workspace = true }
-env_logger = { workspace = true }
 environment = { workspace = true }
-eth2_network_config = { workspace = true }
 execution_layer = { workspace = true }
 futures = { workspace = true }
 kzg = { workspace = true }
diff --git a/testing/simulator/src/main.rs b/testing/simulator/src/main.rs
index 1cc4a1779b..7bd6e546f7 100644
--- a/testing/simulator/src/main.rs
+++ b/testing/simulator/src/main.rs
@@ -18,16 +18,12 @@ mod local_network;
 mod retry;
 
 use cli::cli_app;
-use env_logger::{Builder, Env};
 use local_network::LocalNetwork;
 use types::MinimalEthSpec;
 
 pub type E = MinimalEthSpec;
 
 fn main() {
-    // Debugging output for libp2p and external crates.
-    Builder::from_env(Env::default()).init();
-
     let matches = cli_app().get_matches();
     match matches.subcommand_name() {
         Some("basic-sim") => match basic_sim::run_basic_sim(&matches) {