diff --git a/src/bootstrap/bin/rustc.rs b/src/bootstrap/bin/rustc.rs
index 6f27402233f98..b6ff5786186f3 100644
--- a/src/bootstrap/bin/rustc.rs
+++ b/src/bootstrap/bin/rustc.rs
@@ -115,9 +115,9 @@ fn main() {
     cmd.env("RUSTC_BREAK_ON_ICE", "1");
 
     if let Some(target) = target {
-        // The stage0 compiler has a special sysroot distinct from what we
-        // actually downloaded, so we just always pass the `--sysroot` option.
-        cmd.arg("--sysroot").arg(&sysroot);
+        if !sysroot.is_empty() {
+            cmd.arg("--sysroot").arg(&sysroot);
+        }
 
         // When we build Rust dylibs they're all intended for intermediate
         // usage, so make sure we pass the -Cprefer-dynamic flag instead of
diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index 487440becf630..ff88872697531 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -311,6 +311,8 @@ def __init__(self):
         self._download_url = 'https://static.rust-lang.org'
         self.rustc_channel = ''
         self.build = ''
+        self.host = ''
+        self.check = False
         self.build_dir = os.path.join(os.getcwd(), "build")
         self.clean = False
         self.config_toml = ''
@@ -357,6 +359,16 @@ def download_stage0(self):
                     rustc_channel, self.build)
                 self._download_stage0_helper(filename, "rust-mingw")
 
+        # Download the target libaries used for checking the compiler
+        if self.check and self.host != '' and self.build != self.host and \
+           self.rustc().startswith(self.bin_root()):
+            lib_path = os.path.join(self.bin_root(), "lib", "rustlib", self.host, "lib")
+            if not os.path.exists(lib_path):
+                filename = "rust-std-{}-{}.tar.gz".format(
+                    rustc_channel, self.host)
+                pattern = "rust-std-{}".format(self.host)
+                self._download_stage0_helper(filename, pattern)
+
         if self.cargo().startswith(self.bin_root()) and \
                 (not os.path.exists(self.cargo()) or
                  self.program_out_of_date(self.cargo_stamp())):
@@ -366,6 +378,8 @@ def download_stage0(self):
             with open(self.cargo_stamp(), 'w') as cargo_stamp:
                 cargo_stamp.write(self.date)
 
+        shutil.rmtree(os.path.join(self.build_dir, "cache"), ignore_errors=True)
+
     def _download_stage0_helper(self, filename, pattern):
         cache_dst = os.path.join(self.build_dir, "cache")
         rustc_cache = os.path.join(cache_dst, self.date)
@@ -451,7 +465,7 @@ def rustc_stamp(self):
 
         >>> rb = RustBuild()
         >>> rb.build_dir = "build"
-        >>> rb.rustc_stamp() == os.path.join("build", "stage0", ".rustc-stamp")
+        >>> rb.rustc_stamp() == os.path.join("build", "base", ".rustc-stamp")
         True
         """
         return os.path.join(self.bin_root(), '.rustc-stamp')
@@ -461,7 +475,7 @@ def cargo_stamp(self):
 
         >>> rb = RustBuild()
         >>> rb.build_dir = "build"
-        >>> rb.cargo_stamp() == os.path.join("build", "stage0", ".cargo-stamp")
+        >>> rb.cargo_stamp() == os.path.join("build", "base", ".cargo-stamp")
         True
         """
         return os.path.join(self.bin_root(), '.cargo-stamp')
@@ -478,16 +492,19 @@ def bin_root(self):
 
         >>> rb = RustBuild()
         >>> rb.build_dir = "build"
-        >>> rb.bin_root() == os.path.join("build", "stage0")
+        >>> rb.bin_root() == os.path.join("build", "base")
         True
 
         When the 'build' property is given should be a nested directory:
 
         >>> rb.build = "devel"
-        >>> rb.bin_root() == os.path.join("build", "devel", "stage0")
+        >>> rb.bin_root() == os.path.join("build", "base", "devel")
         True
         """
-        return os.path.join(self.build_dir, self.build, "stage0")
+        if self.build == "":
+            return os.path.join(self.build_dir, "base")
+        else:
+            return os.path.join(self.build_dir, "base", self.build)
 
     def get_toml(self, key):
         """Returns the value of the given key in config.toml, otherwise returns None
@@ -710,6 +727,7 @@ def bootstrap(help_triggered):
     parser = argparse.ArgumentParser(description='Build rust')
     parser.add_argument('--config')
     parser.add_argument('--build')
+    parser.add_argument('--host')
     parser.add_argument('--src')
     parser.add_argument('--clean', action='store_true')
     parser.add_argument('-v', '--verbose', action='count', default=0)
@@ -773,6 +791,8 @@ def bootstrap(help_triggered):
     build.update_submodules()
 
     # Fetch/build the bootstrap
+    build.host = args.host or ''
+    build.check = 'check' in sys.argv
     build.build = args.build or build.build_triple()
     build.download_stage0()
     sys.stdout.flush()
diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 84d2940066931..21c9cd872e49d 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -326,7 +326,7 @@ impl<'a> Builder<'a> {
             }};
         }
         match kind {
-            Kind::Build => describe!(compile::Std, compile::Test, compile::Rustc,
+            Kind::Build => describe!(check::Test, compile::Std, compile::Test, compile::Rustc,
                 compile::StartupObjects, tool::BuildManifest, tool::Rustbook, tool::ErrorIndex,
                 tool::UnstableBookGen, tool::Tidy, tool::Linkchecker, tool::CargoTest,
                 tool::Compiletest, tool::RemoteTestServer, tool::RemoteTestClient,
@@ -624,6 +624,13 @@ impl<'a> Builder<'a> {
         }
 
         let want_rustdoc = self.doc_tests != DocTests::No;
+        let sysroot = if compiler.stage == 0 && !(mode == Mode::Libstd || mode == Mode::Libtest) {
+            // Use the bootstrap compiler's sysroot for stage0
+            // unless we are checking libstd and libtest
+            INTERNER.intern_path(PathBuf::new())
+        } else {
+            self.sysroot(compiler)
+        };
 
         // Customize the compiler we're running. Specify the compiler to cargo
         // as our shim and then pass it some various options used to configure
@@ -637,7 +644,7 @@ impl<'a> Builder<'a> {
              .env("RUSTC_STAGE", stage.to_string())
              .env("RUSTC_DEBUG_ASSERTIONS",
                   self.config.rust_debug_assertions.to_string())
-             .env("RUSTC_SYSROOT", self.sysroot(compiler))
+             .env("RUSTC_SYSROOT", sysroot)
              .env("RUSTC_LIBDIR", self.rustc_libdir(compiler))
              .env("RUSTC_RPATH", self.config.rust_rpath.to_string())
              .env("RUSTDOC", self.out.join("bootstrap/debug/rustdoc"))
@@ -1225,10 +1232,6 @@ mod __test {
             },
         ]);
         assert_eq!(first(builder.cache.all::<compile::Test>()), &[
-            compile::Test {
-                compiler: Compiler { host: a, stage: 0 },
-                target: a,
-            },
             compile::Test {
                 compiler: Compiler { host: a, stage: 1 },
                 target: a,
@@ -1310,10 +1313,6 @@ mod __test {
         ]);
 
         assert_eq!(first(builder.cache.all::<compile::Test>()), &[
-            compile::Test {
-                compiler: Compiler { host: a, stage: 0 },
-                target: a,
-            },
             compile::Test {
                 compiler: Compiler { host: a, stage: 1 },
                 target: a,
@@ -1326,10 +1325,6 @@ mod __test {
                 compiler: Compiler { host: b, stage: 2 },
                 target: a,
             },
-            compile::Test {
-                compiler: Compiler { host: a, stage: 0 },
-                target: b,
-            },
             compile::Test {
                 compiler: Compiler { host: a, stage: 1 },
                 target: b,
@@ -1403,10 +1398,6 @@ mod __test {
         ]);
 
         assert_eq!(first(builder.cache.all::<compile::Test>()), &[
-            compile::Test {
-                compiler: Compiler { host: a, stage: 0 },
-                target: a,
-            },
             compile::Test {
                 compiler: Compiler { host: a, stage: 1 },
                 target: a,
@@ -1419,10 +1410,6 @@ mod __test {
                 compiler: Compiler { host: b, stage: 2 },
                 target: a,
             },
-            compile::Test {
-                compiler: Compiler { host: a, stage: 0 },
-                target: b,
-            },
             compile::Test {
                 compiler: Compiler { host: a, stage: 1 },
                 target: b,
diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
index a516af58b1eab..89efc5c1e5abd 100644
--- a/src/bootstrap/check.rs
+++ b/src/bootstrap/check.rs
@@ -175,6 +175,8 @@ impl Step for Test {
         let compiler = builder.compiler(0, builder.config.build);
         let target = self.target;
 
+        builder.ensure(Std { target });
+
         let out_dir = builder.stage_out(compiler, Mode::Libtest);
         builder.clear_if_dirty(&out_dir, &libstd_stamp(builder, compiler, target));
 
diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 231ed9d40d2de..0d011eaa9ab90 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -438,7 +438,9 @@ impl Step for TestLink {
 
 #[derive(Debug, PartialOrd, Ord, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Rustc {
+    /// The target which our new compiler will run on
     pub target: Interned<String>,
+    /// The compiler we're using to compile rustc
     pub compiler: Compiler,
 }
 
@@ -467,7 +469,9 @@ impl Step for Rustc {
         let compiler = self.compiler;
         let target = self.target;
 
-        builder.ensure(Test { compiler, target });
+        if compiler.stage != 0 {
+            builder.ensure(Test { compiler, target });
+        }
 
         if builder.force_use_stage1(compiler, target) {
             builder.ensure(Rustc {
@@ -485,13 +489,18 @@ impl Step for Rustc {
         }
 
         // Ensure that build scripts have a std to link against.
-        builder.ensure(Std {
-            compiler: builder.compiler(self.compiler.stage, builder.config.build),
-            target: builder.config.build,
-        });
+        if compiler.stage != 0 {
+            builder.ensure(Std {
+                compiler: builder.compiler(self.compiler.stage, builder.config.build),
+                target: builder.config.build,
+            });
+        }
         let cargo_out = builder.cargo_out(compiler, Mode::Librustc, target);
-        builder.clear_if_dirty(&cargo_out, &libstd_stamp(builder, compiler, target));
-        builder.clear_if_dirty(&cargo_out, &libtest_stamp(builder, compiler, target));
+
+        if compiler.stage != 0 {
+            builder.clear_if_dirty(&cargo_out, &libstd_stamp(builder, compiler, target));
+            builder.clear_if_dirty(&cargo_out, &libtest_stamp(builder, compiler, target));
+        }
 
         let mut cargo = builder.cargo(compiler, Mode::Librustc, target, "build");
         rustc_cargo(builder, &mut cargo);
@@ -843,17 +852,9 @@ impl Step for Sysroot {
 
     /// Returns the sysroot for the `compiler` specified that *this build system
     /// generates*.
-    ///
-    /// That is, the sysroot for the stage0 compiler is not what the compiler
-    /// thinks it is by default, but it's the same as the default for stages
-    /// 1-3.
     fn run(self, builder: &Builder) -> Interned<PathBuf> {
         let compiler = self.compiler;
-        let sysroot = if compiler.stage == 0 {
-            builder.out.join(&compiler.host).join("stage0-sysroot")
-        } else {
-            builder.out.join(&compiler.host).join(format!("stage{}", compiler.stage))
-        };
+        let sysroot = builder.out.join(&compiler.host).join(format!("stage{}", compiler.stage));
         let _ = fs::remove_dir_all(&sysroot);
         t!(fs::create_dir_all(&sysroot));
         INTERNER.intern_path(sysroot)
@@ -883,8 +884,9 @@ impl Step for Assemble {
     /// compiler.
     fn run(self, builder: &Builder) -> Compiler {
         let target_compiler = self.target_compiler;
+        let stage = target_compiler.stage;
 
-        if target_compiler.stage == 0 {
+        if stage == 0 {
             assert_eq!(builder.config.build, target_compiler.host,
                 "Cannot obtain compiler for non-native build triple at stage 0");
             // The stage 0 compiler for the build triple is always pre-built.
@@ -921,8 +923,10 @@ impl Step for Assemble {
             for stage in 0..min(target_compiler.stage, builder.config.keep_stage.unwrap()) {
                 let target_compiler = builder.compiler(stage, target_compiler.host);
                 let target = target_compiler.host;
-                builder.ensure(StdLink { compiler, target_compiler, target });
-                builder.ensure(TestLink { compiler, target_compiler, target });
+                if stage != 1 {
+                    builder.ensure(StdLink { compiler, target_compiler, target });
+                    builder.ensure(TestLink { compiler, target_compiler, target });
+                }
                 builder.ensure(RustcLink { compiler, target_compiler, target });
             }
         } else {
@@ -947,7 +951,6 @@ impl Step for Assemble {
             None
         };
 
-        let stage = target_compiler.stage;
         let host = target_compiler.host;
         builder.info(&format!("Assembling stage{} compiler ({})", stage, host));
 
@@ -963,6 +966,16 @@ impl Step for Assemble {
             }
         }
 
+        if stage == 1 {
+            // Copy the dynamic libraries from the bootstrap compiler
+            // which are needed to run the stage1 compiler
+            copy_libs_from_bootstrap(
+                builder,
+                build_compiler,
+                &sysroot_libdir,
+                &["std", "test", "term"]);
+        }
+
         copy_codegen_backends_to_sysroot(builder,
                                          build_compiler,
                                          target_compiler);
@@ -983,6 +996,37 @@ impl Step for Assemble {
     }
 }
 
+fn copy_libs_from_bootstrap(
+    builder: &Builder,
+    compiler: Compiler,
+    out_dir: &Path,
+    libs: &[&str])
+{
+    if builder.config.dry_run {
+        return;
+    }
+
+    let base_libdir = builder.config
+                                .initial_rustc.parent().unwrap()
+                                .parent().unwrap()
+                                .join("lib").join("rustlib").join(compiler.host).join("lib");
+    t!(fs::create_dir_all(&out_dir));
+    let mut files: Vec<PathBuf> = Vec::new();
+    for f in t!(fs::read_dir(&base_libdir)).map(|f| t!(f)) {
+        let filename = f.file_name().into_string().unwrap();
+        let should_copy = is_dylib(&filename) && libs.iter().any(|lib| {
+            filename.starts_with(&format!("{}-", lib)) ||
+            filename.starts_with(&format!("lib{}-", lib))
+        });
+        if !should_copy {
+            continue;
+        }
+        let dest = &out_dir.join(filename);
+        builder.copy(&f.path(), &dest);
+        files.push(dest.into());
+    }
+}
+
 /// Link some files into a rustc sysroot.
 ///
 /// For a particular stage this will link the file listed in `stamp` into the
@@ -1122,6 +1166,11 @@ pub fn run_cargo(builder: &Builder, cargo: &mut Command, stamp: &Path, is_check:
         deps.push(path_to_add.into());
     }
 
+    update_stamp_file(builder, stamp, deps)
+}
+
+pub fn update_stamp_file(builder: &Builder, stamp: &Path, mut deps: Vec<PathBuf>) -> Vec<PathBuf>
+{
     // Now we want to update the contents of the stamp file, if necessary. First
     // we read off the previous contents along with its mtime. If our new
     // contents (the list of files to copy) is different or if any dep's mtime
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index 9840682d1379b..21df3e6d5c221 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -364,7 +364,7 @@ impl Config {
         config.src = Config::path_from_python("SRC");
         config.out = Config::path_from_python("BUILD_DIR");
 
-        let stage0_root = config.out.join(&config.build).join("stage0/bin");
+        let stage0_root = config.out.join("base").join(&config.build).join("bin");
         config.initial_rustc = stage0_root.join(exe("rustc", &config.build));
         config.initial_cargo = stage0_root.join(exe("cargo", &config.build));
 
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index e53fef0678613..266486226e68d 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -51,10 +51,6 @@
 //!
 //!   The build output will be something like the following:
 //!
-//!   Building stage0 std artifacts
-//!   Copying stage0 std
-//!   Building stage0 test artifacts
-//!   Copying stage0 test
 //!   Building stage0 compiler artifacts
 //!   Copying stage0 rustc
 //!   Assembling stage1 compiler
@@ -71,12 +67,12 @@
 //!
 //! Let's disect that a little:
 //!
-//! ## Building stage0 {std,test,compiler} artifacts
+//! ## Building stage0 compiler artifacts
 //!
 //! These steps use the provided (downloaded, usually) compiler to compile the
 //! local Rust source into libraries we can use.
 //!
-//! ## Copying stage0 {std,test,rustc}
+//! ## Copying stage0 rustc
 //!
 //! This copies the build output from Cargo into
 //! `build/$HOST/stage0-sysroot/lib/rustlib/$ARCH/lib`. FIXME: This step's
diff --git a/src/librustc/lib.rs b/src/librustc/lib.rs
index 1d53a305193fa..3fcf1e61b3ec0 100644
--- a/src/librustc/lib.rs
+++ b/src/librustc/lib.rs
@@ -51,8 +51,10 @@
 #![feature(iterator_find_map)]
 #![cfg_attr(windows, feature(libc))]
 #![cfg_attr(stage0, feature(macro_lifetime_matcher))]
+#![cfg_attr(stage0, feature(inclusive_range_methods))]
 #![feature(macro_vis_matcher)]
 #![feature(never_type)]
+#![feature(nonzero)]
 #![feature(exhaustive_patterns)]
 #![feature(non_exhaustive)]
 #![feature(proc_macro_internals)]
diff --git a/src/librustc_codegen_llvm/lib.rs b/src/librustc_codegen_llvm/lib.rs
index 0b0bab96dfdfd..da95f2ceb74b8 100644
--- a/src/librustc_codegen_llvm/lib.rs
+++ b/src/librustc_codegen_llvm/lib.rs
@@ -18,6 +18,7 @@
       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
       html_root_url = "https://doc.rust-lang.org/nightly/")]
 
+#![cfg_attr(stage0, feature(inclusive_range_methods))]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(custom_attribute)]
diff --git a/src/librustc_data_structures/lib.rs b/src/librustc_data_structures/lib.rs
index 9a6705fe9cac3..5d0ed344cc1a1 100644
--- a/src/librustc_data_structures/lib.rs
+++ b/src/librustc_data_structures/lib.rs
@@ -27,6 +27,7 @@
 #![feature(specialization)]
 #![feature(optin_builtin_traits)]
 #![feature(macro_vis_matcher)]
+#![feature(nonzero)]
 #![feature(allow_internal_unstable)]
 
 #![cfg_attr(unix, feature(libc))]
diff --git a/src/librustc_mir/lib.rs b/src/librustc_mir/lib.rs
index 3bf9453fb513c..14e223d59fa48 100644
--- a/src/librustc_mir/lib.rs
+++ b/src/librustc_mir/lib.rs
@@ -14,6 +14,7 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 
 */
 
+#![cfg_attr(stage0, feature(inclusive_range_methods))]
 #![feature(slice_patterns)]
 #![feature(slice_sort_by_cached_key)]
 #![feature(from_ref)]
@@ -26,6 +27,7 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 #![feature(decl_macro)]
 #![feature(fs_read_write)]
 #![feature(macro_vis_matcher)]
+#![feature(nonzero)]
 #![feature(exhaustive_patterns)]
 #![feature(range_contains)]
 #![feature(rustc_diagnostic_macros)]
diff --git a/src/librustc_target/lib.rs b/src/librustc_target/lib.rs
index 8f4911574398b..560741cfd3cdc 100644
--- a/src/librustc_target/lib.rs
+++ b/src/librustc_target/lib.rs
@@ -29,6 +29,7 @@
 #![feature(const_fn)]
 #![feature(fs_read_write)]
 #![feature(inclusive_range)]
+#![cfg_attr(stage0, feature(inclusive_range_methods))]
 #![feature(slice_patterns)]
 
 #[macro_use]