Minor logging tweaks

Some things I noticed from bytecodealliance#7239 which are very much not critical but I
figure might be nice-to-haves:

* Move the logging configuration to the `wasmtime-cli-flags` crate with
  the other logging configuration to keep it in one place.
* Remove `pretty_env_logger` since `tracing-subscriber` probably
  supplants it.
* Don't explicitly inherit env vars in tests since that happens
  automatically with `Command`.

Cargo.toml

@@ -39,7 +39,6 @@ wasmtime-runtime = { workspace = true }
 clap = { workspace = true, features = ["color", "suggestions", "derive"] }
 anyhow = { workspace = true }
 target-lexicon = { workspace = true }
-tracing-subscriber = { workspace = true }
 once_cell = { workspace = true }
 listenfd = "1.0.0"
 wat = { workspace = true }

crates/cli-flags/Cargo.toml

@@ -12,7 +12,7 @@ edition.workspace = true
 anyhow = { workspace = true }
 clap = { workspace = true }
 file-per-thread-logger = { workspace = true }
-pretty_env_logger = { workspace = true }
+tracing-subscriber = { workspace = true }
 rayon = "1.5.0"
 wasmtime = { workspace = true }
 humantime = "2.0.0"

crates/cli-flags/src/lib.rs

@@ -5,7 +5,9 @@
 
 use anyhow::Result;
 use clap::Parser;
+use std::io::IsTerminal;
 use std::time::Duration;
+use tracing_subscriber::{EnvFilter, FmtSubscriber};
 use wasmtime::Config;
 
 pub mod opt;
@@ -328,7 +330,13 @@ impl CommonOptions {
  let prefix = "wasmtime.dbg.";
  init_file_per_thread_logger(prefix);
  } else {
- pretty_env_logger::init();
+ let mut b = FmtSubscriber::builder()
+ .with_writer(std::io::stderr)
+ .with_env_filter(EnvFilter::from_env("WASMTIME_LOG"));
+ if std::io::stderr().is_terminal() {
+ b = b.with_ansi(true);
+ }
+ b.init();
  }
  }
 

src/bin/wasmtime.rs

@@ -82,16 +82,6 @@ impl Wasmtime {
 }
 
 fn main() -> Result<()> {
- use std::io::IsTerminal;
- use tracing_subscriber::{EnvFilter, FmtSubscriber};
-
- let mut b = FmtSubscriber::builder()
- .with_writer(std::io::stderr)
- .with_env_filter(EnvFilter::from_env("WASMTIME_LOG"));
- if std::io::stderr().is_terminal() {
- b = b.with_ansi(true);
- }
- b.init();
  Wasmtime::parse().execute()
 }
 

tests/all/cli_tests.rs

@@ -32,7 +32,7 @@ pub fn get_wasmtime_command() -> Result<Command> {
  // If we're running tests with a "runner" then we might be doing something
  // like cross-emulation, so spin up the emulator rather than the tests
  // itself, which may not be natively executable.
- let mut cmd = if let Some((_, runner)) = runner {
+ let cmd = if let Some((_, runner)) = runner {
  let mut parts = runner.split_whitespace();
  let mut cmd = Command::new(parts.next().unwrap());
  for arg in parts {
@@ -44,10 +44,6 @@ pub fn get_wasmtime_command() -> Result<Command> {
  Command::new(&me)
  };
 
- if let Ok(val) = std::env::var("WASMTIME_LOG") {
- cmd.env("WASMTIME_LOG", val);
- }
-
  Ok(cmd)
 }