Remove fern-based logging as it was never that useful due to the inability to set per-crate log levels

Cargo.lock

@@ -299,14 +299,6 @@ dependencies = [
  "backtrace 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "fern"
-version = "0.3.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "filetime"
 version = "0.1.15"
@@ -982,7 +974,6 @@ dependencies = [
  "daemonize 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "fern 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "filetime 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-cpupool 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1609,7 +1600,6 @@ dependencies = [
 "checksum env_logger 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3ddf21e73e016298f5cb37d6ef8e8da8e39f91f9ec8b0df44b7deb16a9f8cd5b"
 "checksum environment 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1f4b14e20978669064c33b4c1e0fb4083412e40fe56cbea2eae80fd7591503ee"
 "checksum error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ff511d5dc435d703f4971bc399647c9bc38e20cb41452e3b9feb4765419ed3f3"
-"checksum fern 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "4d2f58d053ad7791bfaad58a3f3541fe2d2aecc564dd82aee7f92fa402c054b2"
 "checksum filetime 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)" = "714653f3e34871534de23771ac7b26e999651a0a228f47beb324dfdf1dd4b10f"
 "checksum flate2 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)" = "e6234dd4468ae5d1e2dbb06fe2b058696fdc50a339c68a393aefbf00bc81e423"
 "checksum foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f6f339eb8adc052cd2ca78910fda869aefa38d22d5cb648e6485e4d3fc06f3b1"

Cargo.toml

@@ -22,7 +22,6 @@ chrono = { version = "0.3", optional = true }
 clap = "2.23.0"
 env_logger = "0.4"
 error-chain = { version = "0.11", default-features = false }
-fern = "0.3.5"
 filetime = "0.1"
 futures = "0.1.11"
 futures-cpupool = "0.1"

README.md

@@ -89,11 +89,9 @@ By default, SCCACHE on GCS will be read-only. To change this, set `SCCACHE_GCS_R
 Debugging
 ---------
 
-You can set the `SCCACHE_LOG_LEVEL` environment variable to `debug` or `trace` (not recommended, it's *very verbose*) to cause sccache to output more fine grained logging about what it is doing. A log file named `sccache.log` will be output in the current working directory whenever sccache is invoked.
+You can run the server manually in foreground mode by running `SCCACHE_START_SERVER=1 SCCACHE_NO_DAEMON=1 sccache`, and send logging to stderr by setting the `RUST_LOG` environment variable, the format of which is described in more detail in the [env_logger](https://docs.rs/env_logger/0.5.3/env_logger/#enabling-logging) documentation.
 
-Alternately, you can run the server manually in foreground mode by running `SCCACHE_START_SERVER=1 SCCACHE_NO_DAEMON=1 sccache`, and send logging to stderr by setting the `RUST_LOG` environment variable, the format of which is described in more detail in the [env_logger](http://burntsushi.net/rustdoc/env_logger/index.html#enabling-logging) documentation.
-
-You can set the `SCCACHE_ERROR_LOG` environment variable to a path to cause the server process to redirect its standard error output there, in order to capture the output of unhandled panics. (The server sets `RUST_BACKTRACE=1` internally.)
+Alternately, you can set the `SCCACHE_ERROR_LOG` environment variable to a path and set `RUST_LOG` to get the server process to redirect its logging there (including the output of unhandled panics, since the server sets `RUST_BACKTRACE=1` internally).
 
 ---
 

src/main.rs

@@ -47,7 +47,6 @@ extern crate local_encoding;
 #[macro_use]
 extern crate log;
 extern crate lru_disk_cache;
-extern crate fern;
 #[cfg(test)]
 extern crate itertools;
 extern crate libc;
@@ -136,37 +135,10 @@ fn main() {
 }
 
 fn init_logging() {
-    match if env::var("RUST_LOG").is_ok() {
-        env_logger::init()
-            .map_err(|e| format!("{:?}", e))
-    } else {
-        match env::var("SCCACHE_LOG_LEVEL") {
-            Ok(log_level) => {
-                let log_level = match &*log_level.to_lowercase() {
-                    "off" => log::LogLevelFilter::Off,
-                    "trace" => log::LogLevelFilter::Trace,
-                    "debug" => log::LogLevelFilter::Debug,
-                    "info" => log::LogLevelFilter::Info,
-                    "warn" => log::LogLevelFilter::Warn,
-                    "error" => log::LogLevelFilter::Error,
-                    _ => panic!("Invalid log level {}", log_level),
-                };
-
-                let logger_config = fern::DispatchConfig {
-                    format: Box::new(|msg: &str, level: &log::LogLevel, _location: &log::LogLocation| {
-                        format!("[{}][{}] {}", time::now().strftime("%Y-%m-%d][%H:%M:%S").unwrap(), level, msg)
-                    }),
-                    //TODO: only the server process should output to the log file.
-                    output: vec![fern::OutputConfig::stdout(), fern::OutputConfig::file("sccache.log")],
-                    level: log::LogLevelFilter::Trace,
-                };
-                fern::init_global_logger(logger_config, log_level)
-                    .map_err(|e| format!("{:?}", e))
-            },
-            Err(_) => Ok(()),
+    if env::var("RUST_LOG").is_ok() {
+        match env_logger::init() {
+            Ok(_) => (),
+            Err(e) => panic!(format!("Failed to initalize logging: {:?}", e)),
         }
-    } {
-        Ok(_) => (),
-        Err(e) => panic!(format!("Failed to initalize logging: {}", e)),
     }
 }