diff --git a/src/bootstrap/build/check.rs b/src/bootstrap/build/check.rs
index d4e344fc48247..6aad49bc9880e 100644
--- a/src/bootstrap/build/check.rs
+++ b/src/bootstrap/build/check.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use std::fs;
+
 use build::{Build, Compiler};
 
 pub fn linkcheck(build: &Build, stage: u32, host: &str) {
@@ -29,9 +31,16 @@ pub fn cargotest(build: &Build, stage: u32, host: &str) {
     let sep = if cfg!(windows) { ";" } else {":" };
     let ref newpath = format!("{}{}{}", path.display(), sep, old_path);
 
+    // Note that this is a short, cryptic, and not scoped directory name. This
+    // is currently to minimize the length of path on Windows where we otherwise
+    // quickly run into path name limit constraints.
+    let out_dir = build.out.join("ct");
+    t!(fs::create_dir_all(&out_dir));
+
     build.run(build.tool_cmd(compiler, "cargotest")
-              .env("PATH", newpath)
-              .arg(&build.cargo));
+                   .env("PATH", newpath)
+                   .arg(&build.cargo)
+                   .arg(&out_dir));
 }
 
 pub fn tidy(build: &Build, stage: u32, host: &str) {
diff --git a/src/bootstrap/build/step.rs b/src/bootstrap/build/step.rs
index 2312f96348c9d..07cfb96c30d57 100644
--- a/src/bootstrap/build/step.rs
+++ b/src/bootstrap/build/step.rs
@@ -318,7 +318,8 @@ impl<'a> Step<'a> {
                 vec![self.tool_linkchecker(stage), self.doc(stage)]
             }
             Source::CheckCargoTest { stage } => {
-                vec![self.tool_cargotest(stage)]
+                vec![self.tool_cargotest(stage),
+                     self.librustc(self.compiler(stage))]
             }
             Source::CheckTidy { stage } => {
                 vec![self.tool_tidy(stage)]
@@ -333,7 +334,7 @@ impl<'a> Step<'a> {
                 vec![self.librustc(self.compiler(stage))]
             }
             Source::ToolCargoTest { stage } => {
-                vec![self.librustc(self.compiler(stage))]
+                vec![self.libstd(self.compiler(stage))]
             }
 
             Source::DistDocs { stage } => vec![self.doc(stage)],
diff --git a/src/rustc/Cargo.lock b/src/rustc/Cargo.lock
index 4b5c2850dab08..a3420d75218fb 100644
--- a/src/rustc/Cargo.lock
+++ b/src/rustc/Cargo.lock
@@ -73,7 +73,7 @@ dependencies = [
  "rbml 0.0.0",
  "rustc_back 0.0.0",
  "rustc_bitflags 0.0.0",
- "rustc_const_eval 0.0.0",
+ "rustc_const_math 0.0.0",
  "rustc_data_structures 0.0.0",
  "serialize 0.0.0",
  "syntax 0.0.0",
@@ -106,6 +106,19 @@ dependencies = [
 [[package]]
 name = "rustc_const_eval"
 version = "0.0.0"
+dependencies = [
+ "graphviz 0.0.0",
+ "log 0.0.0",
+ "rustc 0.0.0",
+ "rustc_back 0.0.0",
+ "rustc_const_math 0.0.0",
+ "serialize 0.0.0",
+ "syntax 0.0.0",
+]
+
+[[package]]
+name = "rustc_const_math"
+version = "0.0.0"
 dependencies = [
  "log 0.0.0",
  "serialize 0.0.0",
@@ -131,6 +144,8 @@ dependencies = [
  "rustc 0.0.0",
  "rustc_back 0.0.0",
  "rustc_borrowck 0.0.0",
+ "rustc_const_eval 0.0.0",
+ "rustc_incremental 0.0.0",
  "rustc_lint 0.0.0",
  "rustc_llvm 0.0.0",
  "rustc_metadata 0.0.0",
@@ -147,6 +162,19 @@ dependencies = [
  "syntax_ext 0.0.0",
 ]
 
+[[package]]
+name = "rustc_incremental"
+version = "0.0.0"
+dependencies = [
+ "graphviz 0.0.0",
+ "log 0.0.0",
+ "rbml 0.0.0",
+ "rustc 0.0.0",
+ "rustc_data_structures 0.0.0",
+ "serialize 0.0.0",
+ "syntax 0.0.0",
+]
+
 [[package]]
 name = "rustc_lint"
 version = "0.0.0"
@@ -154,6 +182,7 @@ dependencies = [
  "log 0.0.0",
  "rustc 0.0.0",
  "rustc_back 0.0.0",
+ "rustc_const_eval 0.0.0",
  "syntax 0.0.0",
 ]
 
@@ -176,7 +205,7 @@ dependencies = [
  "rustc 0.0.0",
  "rustc_back 0.0.0",
  "rustc_bitflags 0.0.0",
- "rustc_const_eval 0.0.0",
+ "rustc_const_math 0.0.0",
  "rustc_llvm 0.0.0",
  "serialize 0.0.0",
  "syntax 0.0.0",
@@ -191,6 +220,7 @@ dependencies = [
  "rustc 0.0.0",
  "rustc_back 0.0.0",
  "rustc_const_eval 0.0.0",
+ "rustc_const_math 0.0.0",
  "rustc_data_structures 0.0.0",
  "syntax 0.0.0",
 ]
@@ -201,6 +231,7 @@ version = "0.0.0"
 dependencies = [
  "log 0.0.0",
  "rustc 0.0.0",
+ "rustc_const_eval 0.0.0",
  "syntax 0.0.0",
 ]
 
@@ -247,7 +278,6 @@ version = "0.0.0"
 dependencies = [
  "log 0.0.0",
  "rustc 0.0.0",
- "rustc_front 0.0.0",
  "syntax 0.0.0",
 ]
 
@@ -262,7 +292,9 @@ dependencies = [
  "rustc 0.0.0",
  "rustc_back 0.0.0",
  "rustc_const_eval 0.0.0",
+ "rustc_const_math 0.0.0",
  "rustc_data_structures 0.0.0",
+ "rustc_incremental 0.0.0",
  "rustc_llvm 0.0.0",
  "rustc_mir 0.0.0",
  "rustc_platform_intrinsics 0.0.0",
@@ -280,6 +312,7 @@ dependencies = [
  "rustc 0.0.0",
  "rustc_back 0.0.0",
  "rustc_const_eval 0.0.0",
+ "rustc_const_math 0.0.0",
  "rustc_platform_intrinsics 0.0.0",
  "syntax 0.0.0",
 ]
@@ -294,6 +327,7 @@ dependencies = [
  "log 0.0.0",
  "rustc 0.0.0",
  "rustc_back 0.0.0",
+ "rustc_const_eval 0.0.0",
  "rustc_driver 0.0.0",
  "rustc_lint 0.0.0",
  "rustc_metadata 0.0.0",
diff --git a/src/tools/cargotest/Cargo.lock b/src/tools/cargotest/Cargo.lock
index 30b1427733307..bafde903baa44 100644
--- a/src/tools/cargotest/Cargo.lock
+++ b/src/tools/cargotest/Cargo.lock
@@ -1,28 +1,4 @@
 [root]
 name = "cargotest"
 version = "0.1.0"
-dependencies = [
- "tempdir 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "libc"
-version = "0.2.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "rand"
-version = "0.3.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "libc 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "tempdir"
-version = "0.3.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
-]
 
diff --git a/src/tools/cargotest/Cargo.toml b/src/tools/cargotest/Cargo.toml
index 2c7e235e0b506..8108c7f762eeb 100644
--- a/src/tools/cargotest/Cargo.toml
+++ b/src/tools/cargotest/Cargo.toml
@@ -3,9 +3,6 @@ name = "cargotest"
 version = "0.1.0"
 authors = ["Brian Anderson <banderson@mozilla.com>"]
 
-[dependencies]
-tempdir = "0.3.4"
-
 [[bin]]
 name = "cargotest"
 path = "main.rs"
diff --git a/src/tools/cargotest/main.rs b/src/tools/cargotest/main.rs
index 87a0103867595..7ad54c5bf6be4 100644
--- a/src/tools/cargotest/main.rs
+++ b/src/tools/cargotest/main.rs
@@ -8,73 +8,90 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern crate tempdir;
-
-use tempdir::TempDir;
 use std::env;
 use std::process::Command;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::fs::File;
 use std::io::Write;
 
-const TEST_REPOS: &'static [(&'static str, &'static str, Option<&'static str>)] = &[
-    ("https://github.com/rust-lang/cargo",
-     "fae9c539388f1b7c70c31fd0a21b5dd9cd071177",
-     None),
-    ("https://github.com/iron/iron",
-     "16c858ec2901e2992fe5e529780f59fa8ed12903",
-     Some(include_str!("lockfiles/iron-Cargo.lock")))
+struct Test {
+    repo: &'static str,
+    name: &'static str,
+    sha: &'static str,
+    lock: Option<&'static str>,
+}
+
+const TEST_REPOS: &'static [Test] = &[
+    Test {
+        name: "cargo",
+        repo: "https://github.com/rust-lang/cargo",
+        sha: "fae9c539388f1b7c70c31fd0a21b5dd9cd071177",
+        lock: None,
+    },
+    Test {
+        name: "iron",
+        repo: "https://github.com/iron/iron",
+        sha: "16c858ec2901e2992fe5e529780f59fa8ed12903",
+        lock: Some(include_str!("lockfiles/iron-Cargo.lock")),
+    },
 ];
 
 
 fn main() {
-    let ref cargo = env::args().collect::<Vec<_>>()[1];
+    let args = env::args().collect::<Vec<_>>();
+    let ref cargo = args[1];
+    let out_dir = Path::new(&args[2]);
     let ref cargo = Path::new(cargo);
 
-    for &(repo, sha, lockfile) in TEST_REPOS.iter().rev() {
-        test_repo(cargo, repo, sha, lockfile);
+    for test in TEST_REPOS.iter().rev() {
+        test_repo(cargo, out_dir, test);
     }
 }
 
-fn test_repo(cargo: &Path, repo: &str, sha: &str, lockfile: Option<&str>) {
-    println!("testing {}", repo);
-    let dir = clone_repo(repo, sha);
-    if let Some(lockfile) = lockfile {
-        File::create(&dir.path().join("Cargo.lock")).expect("")
+fn test_repo(cargo: &Path, out_dir: &Path, test: &Test) {
+    println!("testing {}", test.repo);
+    let dir = clone_repo(test, out_dir);
+    if let Some(lockfile) = test.lock {
+        File::create(&dir.join("Cargo.lock")).expect("")
             .write_all(lockfile.as_bytes()).expect("");
     }
-    if !run_cargo_test(cargo, dir.path()) {
-        panic!("tests failed for {}", repo);
+    if !run_cargo_test(cargo, &dir) {
+        panic!("tests failed for {}", test.repo);
     }
 }
 
-fn clone_repo(repo: &str, sha: &str) -> TempDir {
-    let dir = TempDir::new("cargotest").expect("");
-    let status = Command::new("git")
-        .arg("init")
-        .arg(dir.path())
-        .status()
-        .expect("");
-    assert!(status.success());
+fn clone_repo(test: &Test, out_dir: &Path) -> PathBuf {
+    let out_dir = out_dir.join(test.name);
 
-    // Try progressively deeper fetch depths to find the commit
-    let mut found = false;
-    for depth in &[1, 10, 100, 1000, 100000] {
+    if !out_dir.join(".git").is_dir() {
         let status = Command::new("git")
-            .arg("fetch")
-            .arg(repo)
-            .arg("master")
-            .arg(&format!("--depth={}", depth))
-            .current_dir(dir.path())
+            .arg("init")
+            .arg(&out_dir)
             .status()
             .expect("");
         assert!(status.success());
+    }
+
+    // Try progressively deeper fetch depths to find the commit
+    let mut found = false;
+    for depth in &[0, 1, 10, 100, 1000, 100000] {
+        if *depth > 0 {
+            let status = Command::new("git")
+                .arg("fetch")
+                .arg(test.repo)
+                .arg("master")
+                .arg(&format!("--depth={}", depth))
+                .current_dir(&out_dir)
+                .status()
+                .expect("");
+            assert!(status.success());
+        }
 
         let status = Command::new("git")
             .arg("reset")
-            .arg(sha)
+            .arg(test.sha)
             .arg("--hard")
-            .current_dir(dir.path())
+            .current_dir(&out_dir)
             .status()
             .expect("");
 
@@ -84,9 +101,18 @@ fn clone_repo(repo: &str, sha: &str) -> TempDir {
         }
     }
 
-    if !found { panic!("unable to find commit {}", sha) }
+    if !found {
+        panic!("unable to find commit {}", test.sha)
+    }
+    let status = Command::new("git")
+        .arg("clean")
+        .arg("-fdx")
+        .current_dir(&out_dir)
+        .status()
+        .unwrap();
+    assert!(status.success());
 
-    dir
+    out_dir
 }
 
 fn run_cargo_test(cargo_path: &Path, crate_path: &Path) -> bool {