add tracing

src/build.rs

@@ -1,9 +1,9 @@
-use anyhow::{Context, Result};
+use anyhow::{bail, Context, Result};
 use rustfix::diagnostics::Diagnostic;
 use serde::Deserialize;
 use std::{collections::HashSet, fmt::Display, path::PathBuf, process::Command, rc::Rc};
 
-use crate::Options;
+use crate::{EnvVar, Options};
 
 #[derive(Debug, Clone)]
 pub struct Build {
@@ -15,6 +15,7 @@ struct BuildInner {
     mode: BuildMode,
     input_path: PathBuf,
     no_verify: bool,
+    env: Vec<EnvVar>,
 }
 
 #[derive(Debug)]
@@ -38,11 +39,13 @@ impl Build {
                     .map(|cmd| cmd.split_whitespace().map(ToString::to_string).collect()),
             }
         };
+
         Self {
             inner: Rc::new(BuildInner {
                 mode,
                 input_path: options.path.clone(),
                 no_verify: options.no_verify,
+                env: options.env.clone(),
             }),
         }
     }
@@ -52,10 +55,11 @@ impl Build {
             return Ok(BuildResult {
                 reproduces_issue: false,
                 no_verify: true,
+                output: String::new(),
             });
         }
 
-        let reproduces_issue = match &self.inner.mode {
+        let (reproduces_issue, output) = match &self.inner.mode {
             BuildMode::Cargo { args } => {
                 let mut cmd = Command::new("cargo");
                 cmd.arg("build");
@@ -64,33 +68,58 @@ impl Build {
                     cmd.arg(arg);
                 }
 
-                let output =
-                    String::from_utf8(cmd.output().context("spawning rustc process")?.stderr)
-                        .unwrap();
+                for env in &self.inner.env {
+                    cmd.env(&env.key, &env.value);
+                }
 
-                output.contains("internal compiler error")
+                let outputs = cmd.output().context("spawning rustc process")?;
+
+                let output = String::from_utf8(outputs.stderr)?;
+
+                (
+                    outputs.status.code() == Some(101)
+                        || output.contains("internal compiler error"),
+                    output,
+                )
             }
             BuildMode::Script(script_path) => {
                 let mut cmd = Command::new(script_path);
 
-                cmd.output().context("spawning script")?.status.success()
+                for env in &self.inner.env {
+                    cmd.env(&env.key, &env.value);
+                }
+
+                let outputs = cmd.output().context("spawning script")?;
+
+                let output = String::from_utf8(outputs.stderr)?;
+
+                (outputs.status.success(), output)
             }
             BuildMode::Rustc => {
                 let mut cmd = Command::new("rustc");
-                cmd.args(["--edition", "2018"]);
+                cmd.args(["--edition", "2021"]);
                 cmd.arg(&self.inner.input_path);
 
-                cmd.output()
-                    .context("spawning rustc process")?
-                    .status
-                    .code()
-                    == Some(101)
+                for env in &self.inner.env {
+                    cmd.env(&env.key, &env.value);
+                }
+
+                let outputs = cmd.output().context("spawning rustc process")?;
+
+                let output = String::from_utf8(outputs.stderr)?;
+
+                (
+                    outputs.status.code() == Some(101)
+                        || output.contains("internal compiler error"),
+                    output,
+                )
             }
         };
 
         Ok(BuildResult {
             reproduces_issue,
             no_verify: self.inner.no_verify,
+            output,
         })
     }
 
@@ -104,6 +133,10 @@ impl Build {
                     cmd.arg(arg);
                 }
 
+                for env in &self.inner.env {
+                    cmd.env(&env.key, &env.value);
+                }
+
                 let cmd_output = cmd.output()?;
                 let output = String::from_utf8(cmd_output.stdout.clone())?;
 
@@ -121,9 +154,13 @@ impl Build {
             }
             BuildMode::Rustc => {
                 let mut cmd = std::process::Command::new("rustc");
-                cmd.args(["--edition", "2018", "--error-format=json"]);
+                cmd.args(["--edition", "2021", "--error-format=json"]);
                 cmd.arg(&self.inner.input_path);
 
+                for env in &self.inner.env {
+                    cmd.env(&env.key, &env.value);
+                }
+
                 let output = cmd.output()?.stderr;
                 let output = String::from_utf8(output)?;
 
@@ -153,9 +190,20 @@ impl Build {
 pub struct BuildResult {
     reproduces_issue: bool,
     no_verify: bool,
+    output: String,
 }
 
 impl BuildResult {
+    pub fn require_reproduction(&self, build: &str) -> Result<()> {
+        if !self.reproduces_issue() {
+            bail!(
+                "{build} build must reproduce issue. Output:\n{}",
+                self.output
+            );
+        }
+        Ok(())
+    }
+
     pub fn reproduces_issue(&self) -> bool {
         self.reproduces_issue || self.no_verify
     }

src/lib.rs

@@ -1,4 +1,7 @@
-use std::path::PathBuf;
+#[macro_use]
+extern crate tracing;
+
+use std::{path::PathBuf, str::FromStr};
 
 mod build;
 mod everybody_loops;
@@ -31,10 +34,35 @@ pub struct Options {
     #[arg(long)]
     no_verify: bool,
 
+    #[arg(long)]
+    env: Vec<EnvVar>,
+
     #[arg(default_value = "src")]
     path: PathBuf,
 }
 
+#[derive(Debug, Clone)]
+struct EnvVar {
+    key: String,
+    value: String,
+}
+
+impl FromStr for EnvVar {
+    type Err = &'static str;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut split = s.split("=");
+        let key = split
+            .next()
+            .ok_or("env var must have KEY=VALUE format")?
+            .to_string();
+        let value = split
+            .next()
+            .ok_or("env var must have KEY=VALUE format")?
+            .to_string();
+        Ok(Self { key, value })
+    }
+}
+
 pub fn minimize() -> Result<()> {
     let Cargo::Minimize(options) = Cargo::parse();
 

src/main.rs

@@ -1,6 +1,18 @@
 use anyhow::Result;
+use tracing::info;
+use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt, EnvFilter, Registry};
 
 fn main() -> Result<()> {
+    let registry = Registry::default().with(EnvFilter::from_default_env());
+
+    info!("Starting cargo-minimize");
+
+    let tree_layer = tracing_tree::HierarchicalLayer::new(2)
+        .with_targets(true)
+        .with_bracketed_fields(true);
+
+    registry.with(tree_layer).init();
+
     cargo_minimize::minimize()?;
 
     Ok(())

src/processor/mod.rs

@@ -1,9 +1,9 @@
 mod files;
 mod reaper;
 
-use std::{borrow::Borrow, collections::HashSet, ffi::OsStr, mem, path::Path};
+use std::{borrow::Borrow, collections::HashSet, ffi::OsStr, fmt::Debug, mem, path::Path};
 
-use anyhow::{ensure, Context, Result};
+use anyhow::{Context, Result};
 
 use crate::{build::Build, processor::files::Changes};
 
@@ -27,6 +27,12 @@ pub trait Processor {
     fn name(&self) -> &'static str;
 }
 
+impl Debug for dyn Processor {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(self.name())
+    }
+}
+
 #[derive(Debug, PartialEq, Eq)]
 pub enum ProcessState {
     NoChange,
@@ -71,10 +77,7 @@ impl Minimizer {
     ) -> Result<()> {
         let inital_build = self.build.build()?;
         println!("Initial build: {}", inital_build);
-        ensure!(
-            inital_build.reproduces_issue(),
-            "Initial build must reproduce issue"
-        );
+        inital_build.require_reproduction("Initial")?;
 
         for mut pass in passes {
             self.run_pass(&mut *pass)?;
@@ -89,7 +92,9 @@ impl Minimizer {
         let mut refresh_and_try_again = false;
 
         loop {
-            println!("Starting a round of {}", pass.name());
+            let span = info_span!("Starting round of pass", name = pass.name());
+            let _enter = span.enter();
+
             let mut changes = Changes::default();
 
             for file in &self.files {
@@ -176,7 +181,7 @@ impl Minimizer {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash)]
 struct AstPath(Vec<String>);
 
 impl Borrow<[String]> for AstPath {
@@ -185,6 +190,12 @@ impl Borrow<[String]> for AstPath {
     }
 }
 
+impl Debug for AstPath {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "AstPath({:?})", self.0)
+    }
+}
+
 #[derive(Debug)]
 pub struct PassController {
     state: PassControllerState,

src/processor/reaper.rs

@@ -5,7 +5,7 @@ use crate::build::Build;
 use super::{
     files::Changes, tracking, Minimizer, PassController, ProcessState, Processor, SourceFile,
 };
-use anyhow::{ensure, Context, Result};
+use anyhow::{Context, Result};
 use proc_macro2::Span;
 use quote::ToTokens;
 use rustfix::{diagnostics::Diagnostic, Suggestion};
@@ -24,10 +24,8 @@ impl Minimizer {
     pub fn delete_dead_code(&mut self) -> Result<()> {
         let inital_build = self.build.build()?;
         println!("Before reaper: {}", inital_build);
-        ensure!(
-            inital_build.reproduces_issue(),
-            "Initial build must reproduce issue"
-        );
+
+        inital_build.require_reproduction("Initial")?;
 
         let (diags, suggestions) = self
             .build