Port code from Cargo and use for progress

A lot of its functionality is unused still, but the goal it to slowly
migrate logging functionality to it. There is also a useful progress bar
which can be ported over later - it depends on this module.

https://github.com/rust-lang/cargo/blob/4c1fa54d10f58d69ac9ff55be68e1b1c25ecb816/src/cargo/util/progress.rs

12 files changed, 553 insertions, 31 deletions

diff --git a/Cargo.lock b/Cargo.lock
index e5ba0961e..fa227869d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -219,6 +219,7 @@ dependencies = [
  "dirs 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "flatbuffers 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fwdansi 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "http 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.12.30 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper-rustls 0.16.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -353,6 +354,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "fwdansi"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "termcolor 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
 name = "h2"
 version = "0.1.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1551,6 +1561,7 @@ dependencies = [
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)" = "a2037ec1c6c1c4f79557762eab1f7eae1f64f6cb418ace90fae88f0942b60139"
 "checksum futures-cpupool 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "ab90cde24b3319636588d0c35fe03b1333857621051837ed769faefb4c2162e4"
+"checksum fwdansi 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "34dd4c507af68d37ffef962063dfa1944ce0dd4d5b82043dbab1dabe088610c3"
 "checksum h2 0.1.23 (registry+https://github.com/rust-lang/crates.io-index)" = "1e42e3daed5a7e17b12a0c23b5b2fbff23a925a570938ebee4baca1a9a1a2240"
 "checksum http 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)" = "eed324f0f0daf6ec10c474f150505af2c143f251722bf9dbd1261bd1f2ee2c1a"
 "checksum http-body 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6741c859c1b2463a423a1dbce98d418e6c3c3fc720fb0d45528657320920292d"
diff --git a/build_extra/rust/BUILD.gn b/build_extra/rust/BUILD.gn
index b1a36fedf..8151eb89f 100644
--- a/build_extra/rust/BUILD.gn
+++ b/build_extra/rust/BUILD.gn
@@ -1480,6 +1480,19 @@ rust_rlib("termcolor") {
   }
 }
 
+rust_rlib("fwdansi") {
+  edition = "2015"
+  source_root = "$cargo_home/registry/src/github.com-1ecc6299db9ec823/fwdansi-1.0.1/src/lib.rs"
+  args = [
+    "--cap-lints",
+    "allow",
+  ]
+  extern_rlib = [
+    "memchr",
+    "termcolor",
+  ]
+}
+
 rust_rlib("textwrap") {
   edition = "2015"
   source_root = "$cargo_home/registry/src/github.com-1ecc6299db9ec823/textwrap-0.11.0/src/lib.rs"
diff --git a/cli/BUILD.gn b/cli/BUILD.gn
index 72cf8710b..20a5b2dee 100644
--- a/cli/BUILD.gn
+++ b/cli/BUILD.gn
@@ -26,6 +26,7 @@ main_extern_rlib = [
   "dirs",
   "flatbuffers",
   "futures",
+  "fwdansi",
   "http",
   "hyper",
   "hyper_rustls",
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 6289f9bb4..9a6d18c1a 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -55,6 +55,7 @@ utime = "0.2.1"
 
 [target.'cfg(windows)'.dependencies]
 winapi = "0.3.7"
+fwdansi = "1.0.1"
 
 [target.'cfg(unix)'.dependencies]
 nix = "0.13.x"
diff --git a/cli/ansi.rs b/cli/ansi.rs
index 32936ace0..ab2347bcd 100644
--- a/cli/ansi.rs
+++ b/cli/ansi.rs
@@ -1,4 +1,6 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+// TODO(ry) Rename this file to colors.rs
+// TODO(ry) Replace ansi_term with termcolor.
 use ansi_term::Color::Black;
 use ansi_term::Color::Fixed;
 use ansi_term::Color::Red;
diff --git a/cli/compiler.rs b/cli/compiler.rs
index dc30758b2..872ed28a2 100644
--- a/cli/compiler.rs
+++ b/cli/compiler.rs
@@ -180,7 +180,7 @@ pub fn compile_async(
   err_check(worker.execute("workerMain()"));
   err_check(worker.execute("compilerMain()"));
 
-  let compiling_job = state.progress.add(format!("Compiling {}", module_name));
+  let compiling_job = state.progress.add("Compile", &module_name);
 
   let resource = worker.state.resource.clone();
   let compiler_rid = resource.rid;
diff --git a/cli/deno_dir.rs b/cli/deno_dir.rs
index 8695b0578..324aa0e32 100644
--- a/cli/deno_dir.rs
+++ b/cli/deno_dir.rs
@@ -647,9 +647,7 @@ fn fetch_remote_source_async(
 ) -> impl Future<Item = Option<ModuleMetaData>, Error = DenoError> {
   use crate::http_util::FetchOnceResult;
 
-  let download_job = deno_dir
-    .progress
-    .add(format!("Downloading {}", module_name));
+  let download_job = deno_dir.progress.add("Download", module_name);
 
   let module_name = module_name.to_owned();
   let filepath = filepath.to_owned();
diff --git a/cli/main.rs b/cli/main.rs
index 05748f5ab..8121e5f7c 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -35,6 +35,7 @@ mod progress;
 mod repl;
 pub mod resolve_addr;
 pub mod resources;
+mod shell;
 mod signal;
 pub mod source_maps;
 mod startup_data;
@@ -158,17 +159,15 @@ fn create_worker_and_state(
   flags: DenoFlags,
   argv: Vec<String>,
 ) -> (Worker, ThreadSafeState) {
+  use crate::shell::Shell;
+  use std::sync::Arc;
+  use std::sync::Mutex;
+  let shell = Arc::new(Mutex::new(Shell::new()));
   let progress = Progress::new();
-  progress.set_callback(|done, completed, total, msg| {
-    if !done {
-      eprint!("\r[{}/{}] {}", completed, total, msg);
-      eprint!("\x1B[K"); // Clear to end of line.
-      return;
-    }
-
-    // print empty line only if progress bar was used
-    if done && total > 0 {
-      eprintln!();
+  progress.set_callback(move |_done, _completed, _total, status, msg| {
+    if !status.is_empty() {
+      let mut s = shell.lock().unwrap();
+      s.status(status, msg).expect("shell problem");
     }
   });
   let state = ThreadSafeState::new(flags, argv, ops::op_selector_std, progress);
diff --git a/cli/permissions.rs b/cli/permissions.rs
index b8830c537..c1878b6ff 100644
--- a/cli/permissions.rs
+++ b/cli/permissions.rs
@@ -499,7 +499,6 @@ fn check_path_white_list(
 
 #[cfg(test)]
 mod tests {
-  #![allow(clippy::cyclomatic_complexity)]
   use super::*;
 
   // Creates vector of strings, Vec<String>
diff --git a/cli/progress.rs b/cli/progress.rs
index a9bfcc37d..c2fa7979f 100644
--- a/cli/progress.rs
+++ b/cli/progress.rs
@@ -12,7 +12,7 @@ impl Progress {
 
   pub fn set_callback<F>(&self, f: F)
   where
-    F: Fn(bool, usize, usize, &str) + Send + Sync + 'static,
+    F: Fn(bool, usize, usize, &str, &str) + Send + Sync + 'static,
   {
     let mut s = self.0.lock().unwrap();
     assert!(s.callback.is_none());
@@ -30,11 +30,17 @@ impl Progress {
     s.job_names.clone()
   }
 
-  pub fn add(&self, name: String) -> Job {
+  pub fn add(&self, status: &str, name: &str) -> Job {
     let mut s = self.0.lock().unwrap();
     let id = s.job_names.len();
-    s.maybe_call_callback(false, s.complete, s.job_names.len() + 1, &name);
-    s.job_names.push(name);
+    s.maybe_call_callback(
+      false,
+      s.complete,
+      s.job_names.len() + 1,
+      status,
+      name,
+    );
+    s.job_names.push(name.to_string());
     Job {
       id,
       inner: self.0.clone(),
@@ -43,11 +49,11 @@ impl Progress {
 
   pub fn done(&self) {
     let s = self.0.lock().unwrap();
-    s.maybe_call_callback(true, s.complete, s.job_names.len(), "");
+    s.maybe_call_callback(true, s.complete, s.job_names.len(), "", "");
   }
 }
 
-type Callback = dyn Fn(bool, usize, usize, &str) + Send + Sync;
+type Callback = dyn Fn(bool, usize, usize, &str, &str) + Send + Sync;
 
 #[derive(Default)]
 struct Inner {
@@ -62,10 +68,11 @@ impl Inner {
     done: bool,
     complete: usize,
     total: usize,
+    status: &str,
     msg: &str,
   ) {
     if let Some(ref cb) = self.callback {
-      cb(done, complete, total, msg);
+      cb(done, complete, total, status, msg);
     }
   }
 
@@ -87,7 +94,7 @@ impl Drop for Job {
     s.complete += 1;
     let name = &s.job_names[self.id];
     let (complete, total) = s.progress();
-    s.maybe_call_callback(false, complete, total, name);
+    s.maybe_call_callback(false, complete, total, "", name);
   }
 }
 
@@ -100,12 +107,12 @@ mod tests {
     let p = Progress::new();
     assert_eq!(p.progress(), (0, 0));
     {
-      let _j1 = p.add("hello".to_string());
+      let _j1 = p.add("status", "hello");
       assert_eq!(p.progress(), (0, 1));
     }
     assert_eq!(p.progress(), (1, 1));
     {
-      let _j2 = p.add("hello".to_string());
+      let _j2 = p.add("status", "hello");
       assert_eq!(p.progress(), (1, 2));
     }
     assert_eq!(p.progress(), (2, 2));
@@ -114,8 +121,8 @@ mod tests {
   #[test]
   fn history() {
     let p = Progress::new();
-    let _a = p.add("a".to_string());
-    let _b = p.add("b".to_string());
+    let _a = p.add("status", "a");
+    let _b = p.add("status", "b");
     assert_eq!(p.history(), vec!["a", "b"]);
   }
 
@@ -127,16 +134,16 @@ mod tests {
       let p = Progress::new();
       let callback_history_ = callback_history.clone();
 
-      p.set_callback(move |_done, complete, total, msg| {
+      p.set_callback(move |_done, complete, total, _status, msg| {
         // println!("callback: {}, {}, {}", complete, total, msg);
         let mut h = callback_history_.lock().unwrap();
         h.push((complete, total, String::from(msg)));
       });
       {
-        let _a = p.add("a".to_string());
-        let _b = p.add("b".to_string());
+        let _a = p.add("status", "a");
+        let _b = p.add("status", "b");
       }
-      let _c = p.add("c".to_string());
+      let _c = p.add("status", "c");
     }
 
     let h = callback_history.lock().unwrap();
diff --git a/cli/shell.rs b/cli/shell.rs
new file mode 100644
index 000000000..4dc388f39
--- /dev/null
+++ b/cli/shell.rs
@@ -0,0 +1,491 @@
+// This file was forked from Cargo on 2019.05.29:
+// https://github.com/rust-lang/cargo/blob/edd874/src/cargo/core/shell.rs
+// Cargo is MIT licenced:
+// https://github.com/rust-lang/cargo/blob/edd874/LICENSE-MIT
+
+#![allow(dead_code)]
+#![allow(irrefutable_let_patterns)]
+
+use std::fmt;
+use std::io::prelude::*;
+
+use atty;
+use termcolor::Color::{Cyan, Green, Red, Yellow};
+use termcolor::{self, Color, ColorSpec, StandardStream, WriteColor};
+
+use crate::deno_error::DenoResult;
+
+/// The requested verbosity of output.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum Verbosity {
+  Verbose,
+  Normal,
+  Quiet,
+}
+
+/// An abstraction around a `Write`able object that remembers preferences for output verbosity and
+/// color.
+pub struct Shell {
+  /// the `Write`able object, either with or without color support (represented by different enum
+  /// variants)
+  err: ShellOut,
+  /// How verbose messages should be
+  verbosity: Verbosity,
+  /// Flag that indicates the current line needs to be cleared before
+  /// printing. Used when a progress bar is currently displayed.
+  needs_clear: bool,
+}
+
+impl fmt::Debug for Shell {
+  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+    match self.err {
+      /*
+      ShellOut::Write(_) => f
+        .debug_struct("Shell")
+        .field("verbosity", &self.verbosity)
+        .finish(),
+      */
+      ShellOut::Stream { color_choice, .. } => f
+        .debug_struct("Shell")
+        .field("verbosity", &self.verbosity)
+        .field("color_choice", &color_choice)
+        .finish(),
+    }
+  }
+}
+
+/// A `Write`able object, either with or without color support
+enum ShellOut {
+  /// A plain write object without color support
+  // TODO(ry) Disabling this type of output because it makes Shell
+  // not thread safe and thus not includable in ThreadSafeState.
+  // But I think we will want this in the future.
+  //Write(Box<dyn Write>),
+  /// Color-enabled stdio, with information on whether color should be used
+  Stream {
+    stream: StandardStream,
+    tty: bool,
+    color_choice: ColorChoice,
+  },
+}
+
+/// Whether messages should use color output
+#[derive(Debug, PartialEq, Clone, Copy)]
+pub enum ColorChoice {
+  /// Force color output
+  Always,
+  /// Force disable color output
+  Never,
+  /// Intelligently guess whether to use color output
+  CargoAuto,
+}
+
+impl Shell {
+  /// Creates a new shell (color choice and verbosity), defaulting to 'auto' color and verbose
+  /// output.
+  pub fn new() -> Shell {
+    Shell {
+      err: ShellOut::Stream {
+        stream: StandardStream::stderr(
+          ColorChoice::CargoAuto.to_termcolor_color_choice(),
+        ),
+        color_choice: ColorChoice::CargoAuto,
+        tty: atty::is(atty::Stream::Stderr),
+      },
+      verbosity: Verbosity::Verbose,
+      needs_clear: false,
+    }
+  }
+
+  /*
+  /// Creates a shell from a plain writable object, with no color, and max verbosity.
+  pub fn from_write(out: Box<dyn Write>) -> Shell {
+    Shell {
+      err: ShellOut::Write(out),
+      verbosity: Verbosity::Verbose,
+      needs_clear: false,
+    }
+  }
+  */
+
+  /// Prints a message, where the status will have `color` color, and can be justified. The
+  /// messages follows without color.
+  fn print(
+    &mut self,
+    status: &dyn fmt::Display,
+    message: Option<&dyn fmt::Display>,
+    color: Color,
+    justified: bool,
+  ) -> DenoResult<()> {
+    match self.verbosity {
+      Verbosity::Quiet => Ok(()),
+      _ => {
+        if self.needs_clear {
+          self.err_erase_line();
+        }
+        self.err.print(status, message, color, justified)
+      }
+    }
+  }
+
+  /// Sets whether the next print should clear the current line.
+  pub fn set_needs_clear(&mut self, needs_clear: bool) {
+    self.needs_clear = needs_clear;
+  }
+
+  /// Returns `true` if the `needs_clear` flag is unset.
+  pub fn is_cleared(&self) -> bool {
+    !self.needs_clear
+  }
+
+  /// Returns the width of the terminal in spaces, if any.
+  pub fn err_width(&self) -> Option<usize> {
+    match self.err {
+      ShellOut::Stream { tty: true, .. } => imp::stderr_width(),
+      _ => None,
+    }
+  }
+
+  /// Returns `true` if stderr is a tty.
+  pub fn is_err_tty(&self) -> bool {
+    match self.err {
+      ShellOut::Stream { tty, .. } => tty,
+      // _ => false,
+    }
+  }
+
+  /// Gets a reference to the underlying writer.
+  pub fn err(&mut self) -> &mut dyn Write {
+    if self.needs_clear {
+      self.err_erase_line();
+    }
+    self.err.as_write()
+  }
+
+  /// Erase from cursor to end of line.
+  pub fn err_erase_line(&mut self) {
+    if let ShellOut::Stream { tty: true, .. } = self.err {
+      imp::err_erase_line(self);
+      self.needs_clear = false;
+    }
+  }
+
+  /// Shortcut to right-align and color green a status message.
+  pub fn status<T, U>(&mut self, status: T, message: U) -> DenoResult<()>
+  where
+    T: fmt::Display,
+    U: fmt::Display,
+  {
+    self.print(&status, Some(&message), Green, false)
+  }
+
+  pub fn status_header<T>(&mut self, status: T) -> DenoResult<()>
+  where
+    T: fmt::Display,
+  {
+    self.print(&status, None, Cyan, true)
+  }
+
+  /// Shortcut to right-align a status message.
+  pub fn status_with_color<T, U>(
+    &mut self,
+    status: T,
+    message: U,
+    color: Color,
+  ) -> DenoResult<()>
+  where
+    T: fmt::Display,
+    U: fmt::Display,
+  {
+    self.print(&status, Some(&message), color, true)
+  }
+
+  /// Runs the callback only if we are in verbose mode.
+  pub fn verbose<F>(&mut self, mut callback: F) -> DenoResult<()>
+  where
+    F: FnMut(&mut Shell) -> DenoResult<()>,
+  {
+    match self.verbosity {
+      Verbosity::Verbose => callback(self),
+      _ => Ok(()),
+    }
+  }
+
+  /// Runs the callback if we are not in verbose mode.
+  pub fn concise<F>(&mut self, mut callback: F) -> DenoResult<()>
+  where
+    F: FnMut(&mut Shell) -> DenoResult<()>,
+  {
+    match self.verbosity {
+      Verbosity::Verbose => Ok(()),
+      _ => callback(self),
+    }
+  }
+
+  /// Prints a red 'error' message.
+  pub fn error<T: fmt::Display>(&mut self, message: T) -> DenoResult<()> {
+    self.print(&"error:", Some(&message), Red, false)
+  }
+
+  /// Prints an amber 'warning' message.
+  pub fn warn<T: fmt::Display>(&mut self, message: T) -> DenoResult<()> {
+    match self.verbosity {
+      Verbosity::Quiet => Ok(()),
+      _ => self.print(&"warning:", Some(&message), Yellow, false),
+    }
+  }
+
+  /// Updates the verbosity of the shell.
+  pub fn set_verbosity(&mut self, verbosity: Verbosity) {
+    self.verbosity = verbosity;
+  }
+
+  /// Gets the verbosity of the shell.
+  pub fn verbosity(&self) -> Verbosity {
+    self.verbosity
+  }
+
+  /// Updates the color choice (always, never, or auto) from a string..
+  pub fn set_color_choice(&mut self, color: Option<&str>) -> DenoResult<()> {
+    if let ShellOut::Stream {
+      ref mut stream,
+      ref mut color_choice,
+      ..
+    } = self.err
+    {
+      let cfg = match color {
+        Some("always") => ColorChoice::Always,
+        Some("never") => ColorChoice::Never,
+
+        Some("auto") | None => ColorChoice::CargoAuto,
+
+        Some(arg) => panic!(
+          "argument for --color must be auto, always, or \
+           never, but found `{}`",
+          arg
+        ),
+      };
+      *color_choice = cfg;
+      *stream = StandardStream::stderr(cfg.to_termcolor_color_choice());
+    }
+    Ok(())
+  }
+
+  /// Gets the current color choice.
+  ///
+  /// If we are not using a color stream, this will always return `Never`, even if the color
+  /// choice has been set to something else.
+  pub fn color_choice(&self) -> ColorChoice {
+    match self.err {
+      ShellOut::Stream { color_choice, .. } => color_choice,
+      // ShellOut::Write(_) => ColorChoice::Never,
+    }
+  }
+
+  /// Whether the shell supports color.
+  pub fn supports_color(&self) -> bool {
+    match &self.err {
+      // ShellOut::Write(_) => false,
+      ShellOut::Stream { stream, .. } => stream.supports_color(),
+    }
+  }
+
+  /// Prints a message and translates ANSI escape code into console colors.
+  pub fn print_ansi(&mut self, message: &[u8]) -> DenoResult<()> {
+    if self.needs_clear {
+      self.err_erase_line();
+    }
+    #[cfg(windows)]
+    {
+      if let ShellOut::Stream { stream, .. } = &mut self.err {
+        ::fwdansi::write_ansi(stream, message)?;
+        return Ok(());
+      }
+    }
+    self.err().write_all(message)?;
+    Ok(())
+  }
+}
+
+impl Default for Shell {
+  fn default() -> Self {
+    Self::new()
+  }
+}
+
+impl ShellOut {
+  /// Prints out a message with a status. The status comes first, and is bold plus the given
+  /// color. The status can be justified, in which case the max width that will right align is
+  /// 12 chars.
+  fn print(
+    &mut self,
+    status: &dyn fmt::Display,
+    message: Option<&dyn fmt::Display>,
+    color: Color,
+    justified: bool,
+  ) -> DenoResult<()> {
+    match *self {
+      ShellOut::Stream { ref mut stream, .. } => {
+        stream.reset()?;
+        stream
+          .set_color(ColorSpec::new().set_bold(true).set_fg(Some(color)))?;
+        if justified {
+          write!(stream, "{:>12}", status)?;
+        } else {
+          write!(stream, "{}", status)?;
+        }
+        stream.reset()?;
+        match message {
+          Some(message) => writeln!(stream, " {}", message)?,
+          None => write!(stream, " ")?,
+        }
+      } /*
+      ShellOut::Write(ref mut w) => {
+        if justified {
+          write!(w, "{:>12}", status)?;
+        } else {
+          write!(w, "{}", status)?;
+        }
+        match message {
+          Some(message) => writeln!(w, " {}", message)?,
+          None => write!(w, " ")?,
+        }
+      }
+      */
+    }
+    Ok(())
+  }
+
+  /// Gets this object as a `io::Write`.
+  fn as_write(&mut self) -> &mut dyn Write {
+    match *self {
+      ShellOut::Stream { ref mut stream, .. } => stream,
+      // ShellOut::Write(ref mut w) => w,
+    }
+  }
+}
+
+impl ColorChoice {
+  /// Converts our color choice to termcolor's version.
+  fn to_termcolor_color_choice(self) -> termcolor::ColorChoice {
+    match self {
+      ColorChoice::Always => termcolor::ColorChoice::Always,
+      ColorChoice::Never => termcolor::ColorChoice::Never,
+      ColorChoice::CargoAuto => {
+        if atty::is(atty::Stream::Stderr) {
+          termcolor::ColorChoice::Auto
+        } else {
+          termcolor::ColorChoice::Never
+        }
+      }
+    }
+  }
+}
+
+#[cfg(any(target_os = "linux", target_os = "macos"))]
+mod imp {
+  use std::mem;
+
+  use libc;
+
+  use super::Shell;
+
+  pub fn stderr_width() -> Option<usize> {
+    unsafe {
+      let mut winsize: libc::winsize = mem::zeroed();
+      if libc::ioctl(libc::STDERR_FILENO, libc::TIOCGWINSZ, &mut winsize) < 0 {
+        return None;
+      }
+      if winsize.ws_col > 0 {
+        Some(winsize.ws_col as usize)
+      } else {
+        None
+      }
+    }
+  }
+
+  pub fn err_erase_line(shell: &mut Shell) {
+    // This is the "EL - Erase in Line" sequence. It clears from the cursor
+    // to the end of line.
+    // https://en.wikipedia.org/wiki/ANSI_escape_code#CSI_sequences
+    let _ = shell.err.as_write().write_all(b"\x1B[K");
+  }
+}
+
+#[cfg(all(unix, not(any(target_os = "linux", target_os = "macos"))))]
+mod imp {
+  pub(super) use super::default_err_erase_line as err_erase_line;
+
+  pub fn stderr_width() -> Option<usize> {
+    None
+  }
+}
+
+#[cfg(windows)]
+mod imp {
+  use std::{cmp, mem, ptr};
+  use winapi::um::fileapi::*;
+  use winapi::um::handleapi::*;
+  use winapi::um::processenv::*;
+  use winapi::um::winbase::*;
+  use winapi::um::wincon::*;
+  use winapi::um::winnt::*;
+
+  pub(super) use super::default_err_erase_line as err_erase_line;
+
+  pub fn stderr_width() -> Option<usize> {
+    unsafe {
+      let stdout = GetStdHandle(STD_ERROR_HANDLE);
+      let mut csbi: CONSOLE_SCREEN_BUFFER_INFO = mem::zeroed();
+      if GetConsoleScreenBufferInfo(stdout, &mut csbi) != 0 {
+        return Some((csbi.srWindow.Right - csbi.srWindow.Left) as usize);
+      }
+
+      // On mintty/msys/cygwin based terminals, the above fails with
+      // INVALID_HANDLE_VALUE. Use an alternate method which works
+      // in that case as well.
+      let h = CreateFileA(
+        "CONOUT$\0".as_ptr() as *const CHAR,
+        GENERIC_READ | GENERIC_WRITE,
+        FILE_SHARE_READ | FILE_SHARE_WRITE,
+        ptr::null_mut(),
+        OPEN_EXISTING,
+        0,
+        ptr::null_mut(),
+      );
+      if h == INVALID_HANDLE_VALUE {
+        return None;
+      }
+
+      let mut csbi: CONSOLE_SCREEN_BUFFER_INFO = mem::zeroed();
+      let rc = GetConsoleScreenBufferInfo(h, &mut csbi);
+      CloseHandle(h);
+      if rc != 0 {
+        let width = (csbi.srWindow.Right - csbi.srWindow.Left) as usize;
+        // Unfortunately cygwin/mintty does not set the size of the
+        // backing console to match the actual window size. This
+        // always reports a size of 80 or 120 (not sure what
+        // determines that). Use a conservative max of 60 which should
+        // work in most circumstances. ConEmu does some magic to
+        // resize the console correctly, but there's no reasonable way
+        // to detect which kind of terminal we are running in, or if
+        // GetConsoleScreenBufferInfo returns accurate information.
+        return Some(cmp::min(60, width));
+      }
+      None
+    }
+  }
+}
+
+#[cfg(
+  any(
+    all(unix, not(any(target_os = "linux", target_os = "macos"))),
+    windows
+  )
+)]
+fn default_err_erase_line(shell: &mut Shell) {
+  if let Some(max_width) = imp::stderr_width() {
+    let blank = " ".repeat(max_width);
+    drop(write!(shell.err.as_write(), "{}\r", blank));
+  }
+}
diff --git a/third_party b/third_party
-Subproject 4c9d6c9f133cae292528d3b68e55249acd8c1b1
+Subproject 159c954ab0e11f655c7cb2a36302c0261c3e121