diff --git a/docs/cli-logging.md b/docs/cli-logging.md index 8a4d26bd1283..7d0b1ba0c575 100644 --- a/docs/cli-logging.md +++ b/docs/cli-logging.md @@ -1,15 +1,16 @@ # Logging in the `wasmtime` CLI Wasmtime's libraries use Rust's [`log`] crate to log diagnostic -information, and the `wasmtime` CLI executable uses [`pretty_env_logger`] -by default for logging this information to the console. +information, and the `wasmtime` CLI executable uses [`tracing-subscriber`] +for displaying this information on the console. Basic logging is controlled by the `WASMTIME_LOG` environment variable. For example, To enable logging of WASI system calls, similar to the `strace` command on Linux, -set `WASMTIME_LOG=wasmtime_wasi=trace`. +set `WASMTIME_LOG=wasmtime_wasi=trace`. For more information on specifying +filters, see [tracing-subscriber's EnvFilter docs]. ```sh -$ WASMTIME_LOG=wasmtime_wasi=trace hello.wasm +$ WASMTIME_LOG=wasmtime_wasi=trace wasmtime hello.wasm [...] TRACE wiggle abi{module="wasi_snapshot_preview1" function="fd_write"} wasmtime_wasi::preview1::wasi_snapshot_preview1 > fd=Fd(1) iovs=*guest 0x14/1 Hello, world! @@ -23,4 +24,5 @@ Wasmtime can also redirect the log messages into log files, with the the files named `wasmtime.dbg.*`. [`log`]: https://crates.io/crates/log -[`pretty_env_logger`]: https://crates.io/crates/pretty_env_logger +[`tracing-subscriber`]: https://crates.io/crates/tracing-subscriber +[tracing-subscriber's EnvFilter docs]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives