diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 0276d15a5b4..d688f798956 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -364,6 +364,19 @@ impl<'a> ShouldRun<'a> {
         self
     }
 
+    // single alias, which does not correspond to any on-disk path
+    pub fn alias(mut self, alias: &str) -> Self {
+        assert!(
+            !self.builder.src.join(alias).exists(),
+            "use `builder.path()` for real paths: {}",
+            alias
+        );
+        self.paths.insert(PathSet::Set(
+            std::iter::once(TaskPath { path: alias.into(), kind: Some(self.kind) }).collect(),
+        ));
+        self
+    }
+
     // single, non-aliased path
     pub fn path(self, path: &str) -> Self {
         self.paths(&[path])
@@ -372,7 +385,17 @@ impl<'a> ShouldRun<'a> {
     // multiple aliases for the same job
     pub fn paths(mut self, paths: &[&str]) -> Self {
         self.paths.insert(PathSet::Set(
-            paths.iter().map(|p| TaskPath { path: p.into(), kind: Some(self.kind) }).collect(),
+            paths
+                .iter()
+                .map(|p| {
+                    assert!(
+                        self.builder.src.join(p).exists(),
+                        "`should_run.paths` should correspond to real on-disk paths - use `alias` if there is no relevant path: {}",
+                        p
+                    );
+                    TaskPath { path: p.into(), kind: Some(self.kind) }
+                })
+                .collect(),
         ));
         self
     }
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index fdd1581d9cd..e3287e35227 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -61,7 +61,7 @@ impl Step for Docs {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = run.builder.config.docs;
-        run.path("rust-docs").default_condition(default)
+        run.alias("rust-docs").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -94,7 +94,7 @@ impl Step for RustcDocs {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
-        run.path("rustc-docs").default_condition(builder.config.compiler_docs)
+        run.alias("rustc-docs").default_condition(builder.config.compiler_docs)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -272,7 +272,7 @@ impl Step for Mingw {
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("rust-mingw")
+        run.alias("rust-mingw")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -313,7 +313,7 @@ impl Step for Rustc {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("rustc")
+        run.alias("rustc")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -456,7 +456,7 @@ impl Step for DebuggerScripts {
     type Output = ();
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/lldb_batchmode.py")
+        run.path("src/etc/lldb_batchmode.py")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -547,7 +547,7 @@ impl Step for Std {
     const DEFAULT: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("rust-std")
+        run.alias("rust-std")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -594,7 +594,7 @@ impl Step for RustcDev {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("rustc-dev")
+        run.alias("rustc-dev")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -653,7 +653,7 @@ impl Step for Analysis {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "analysis");
-        run.path("rust-analysis").default_condition(default)
+        run.alias("rust-analysis").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -790,7 +790,7 @@ impl Step for Src {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("rust-src")
+        run.alias("rust-src")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -848,7 +848,7 @@ impl Step for PlainSourceTarball {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
-        run.path("rustc-src").default_condition(builder.config.rust_dist_src)
+        run.alias("rustc-src").default_condition(builder.config.rust_dist_src)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -942,7 +942,7 @@ impl Step for Cargo {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "cargo");
-        run.path("cargo").default_condition(default)
+        run.alias("cargo").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -998,7 +998,7 @@ impl Step for Rls {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "rls");
-        run.path("rls").default_condition(default)
+        run.alias("rls").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1045,7 +1045,7 @@ impl Step for RustAnalyzer {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "rust-analyzer");
-        run.path("rust-analyzer").default_condition(default)
+        run.alias("rust-analyzer").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1101,7 +1101,7 @@ impl Step for Clippy {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "clippy");
-        run.path("clippy").default_condition(default)
+        run.alias("clippy").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1152,7 +1152,7 @@ impl Step for Miri {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "miri");
-        run.path("miri").default_condition(default)
+        run.alias("miri").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1212,7 +1212,7 @@ impl Step for Rustfmt {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "rustfmt");
-        run.path("rustfmt").default_condition(default)
+        run.alias("rustfmt").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1271,7 +1271,7 @@ impl Step for RustDemangler {
         // we run the step by default when only `extended = true`, and decide whether to actually
         // run it or not later.
         let default = run.builder.config.extended;
-        run.path("rust-demangler").default_condition(default)
+        run.alias("rust-demangler").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1324,7 +1324,7 @@ impl Step for Extended {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
-        run.path("extended").default_condition(builder.config.extended)
+        run.alias("extended").default_condition(builder.config.extended)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -1968,7 +1968,8 @@ impl Step for LlvmTools {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let default = should_build_extended_tool(&run.builder, "llvm-tools");
-        run.path("llvm-tools").default_condition(default)
+        // FIXME: allow using the names of the tools themselves?
+        run.alias("llvm-tools").default_condition(default)
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -2022,7 +2023,7 @@ impl Step for RustDev {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("rust-dev")
+        run.alias("rust-dev")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -2098,7 +2099,7 @@ impl Step for BuildManifest {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("build-manifest")
+        run.alias("build-manifest")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -2130,7 +2131,7 @@ impl Step for ReproducibleArtifacts {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("reproducible-artifacts")
+        run.alias("reproducible-artifacts")
     }
 
     fn make_run(run: RunConfig<'_>) {
diff --git a/src/bootstrap/install.rs b/src/bootstrap/install.rs
index 27b9196d986..08e37a16279 100644
--- a/src/bootstrap/install.rs
+++ b/src/bootstrap/install.rs
@@ -93,7 +93,7 @@ fn prepare_dir(mut path: PathBuf) -> String {
 macro_rules! install {
     (($sel:ident, $builder:ident, $_config:ident),
        $($name:ident,
-       $path:expr,
+       $condition_name: ident = $path_or_alias: literal,
        $default_cond:expr,
        only_hosts: $only_hosts:expr,
        $run_item:block $(, $c:ident)*;)+) => {
@@ -108,7 +108,7 @@ macro_rules! install {
             #[allow(dead_code)]
             fn should_build(config: &Config) -> bool {
                 config.extended && config.tools.as_ref()
-                    .map_or(true, |t| t.contains($path))
+                    .map_or(true, |t| t.contains($path_or_alias))
             }
         }
 
@@ -120,7 +120,7 @@ macro_rules! install {
 
             fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
                 let $_config = &run.builder.config;
-                run.path($path).default_condition($default_cond)
+                run.$condition_name($path_or_alias).default_condition($default_cond)
             }
 
             fn make_run(run: RunConfig<'_>) {
@@ -138,11 +138,11 @@ macro_rules! install {
 }
 
 install!((self, builder, _config),
-    Docs, "src/doc", _config.docs, only_hosts: false, {
+    Docs, path = "src/doc", _config.docs, only_hosts: false, {
         let tarball = builder.ensure(dist::Docs { host: self.target }).expect("missing docs");
         install_sh(builder, "docs", self.compiler.stage, Some(self.target), &tarball);
     };
-    Std, "library/std", true, only_hosts: false, {
+    Std, path = "library/std", true, only_hosts: false, {
         for target in &builder.targets {
             // `expect` should be safe, only None when host != build, but this
             // only runs when host == build
@@ -153,13 +153,13 @@ install!((self, builder, _config),
             install_sh(builder, "std", self.compiler.stage, Some(*target), &tarball);
         }
     };
-    Cargo, "cargo", Self::should_build(_config), only_hosts: true, {
+    Cargo, alias = "cargo", Self::should_build(_config), only_hosts: true, {
         let tarball = builder
             .ensure(dist::Cargo { compiler: self.compiler, target: self.target })
             .expect("missing cargo");
         install_sh(builder, "cargo", self.compiler.stage, Some(self.target), &tarball);
     };
-    Rls, "rls", Self::should_build(_config), only_hosts: true, {
+    Rls, alias = "rls", Self::should_build(_config), only_hosts: true, {
         if let Some(tarball) = builder.ensure(dist::Rls { compiler: self.compiler, target: self.target }) {
             install_sh(builder, "rls", self.compiler.stage, Some(self.target), &tarball);
         } else {
@@ -168,7 +168,7 @@ install!((self, builder, _config),
             );
         }
     };
-    RustAnalyzer, "rust-analyzer", Self::should_build(_config), only_hosts: true, {
+    RustAnalyzer, alias = "rust-analyzer", Self::should_build(_config), only_hosts: true, {
         if let Some(tarball) =
             builder.ensure(dist::RustAnalyzer { compiler: self.compiler, target: self.target })
         {
@@ -179,13 +179,13 @@ install!((self, builder, _config),
             );
         }
     };
-    Clippy, "clippy", Self::should_build(_config), only_hosts: true, {
+    Clippy, alias = "clippy", Self::should_build(_config), only_hosts: true, {
         let tarball = builder
             .ensure(dist::Clippy { compiler: self.compiler, target: self.target })
             .expect("missing clippy");
         install_sh(builder, "clippy", self.compiler.stage, Some(self.target), &tarball);
     };
-    Miri, "miri", Self::should_build(_config), only_hosts: true, {
+    Miri, alias = "miri", Self::should_build(_config), only_hosts: true, {
         if let Some(tarball) = builder.ensure(dist::Miri { compiler: self.compiler, target: self.target }) {
             install_sh(builder, "miri", self.compiler.stage, Some(self.target), &tarball);
         } else {
@@ -194,7 +194,7 @@ install!((self, builder, _config),
             );
         }
     };
-    Rustfmt, "rustfmt", Self::should_build(_config), only_hosts: true, {
+    Rustfmt, alias = "rustfmt", Self::should_build(_config), only_hosts: true, {
         if let Some(tarball) = builder.ensure(dist::Rustfmt {
             compiler: self.compiler,
             target: self.target
@@ -206,7 +206,7 @@ install!((self, builder, _config),
             );
         }
     };
-    RustDemangler, "rust-demangler", Self::should_build(_config), only_hosts: true, {
+    RustDemangler, alias = "rust-demangler", Self::should_build(_config), only_hosts: true, {
         // Note: Even though `should_build` may return true for `extended` default tools,
         // dist::RustDemangler may still return None, unless the target-dependent `profiler` config
         // is also true, or the `tools` array explicitly includes "rust-demangler".
@@ -222,7 +222,7 @@ install!((self, builder, _config),
             );
         }
     };
-    Analysis, "analysis", Self::should_build(_config), only_hosts: false, {
+    Analysis, alias = "analysis", Self::should_build(_config), only_hosts: false, {
         // `expect` should be safe, only None with host != build, but this
         // only uses the `build` compiler
         let tarball = builder.ensure(dist::Analysis {
@@ -234,7 +234,7 @@ install!((self, builder, _config),
         }).expect("missing analysis");
         install_sh(builder, "analysis", self.compiler.stage, Some(self.target), &tarball);
     };
-    Rustc, "src/librustc", true, only_hosts: true, {
+    Rustc, path = "compiler/rustc", true, only_hosts: true, {
         let tarball = builder.ensure(dist::Rustc {
             compiler: builder.compiler(builder.top_stage, self.target),
         });
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index 6d7ca9a94cf..73fb2dad1e3 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -122,7 +122,7 @@ impl Step for Llvm {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/llvm-project").path("src/llvm-project/llvm").path("src/llvm")
+        run.path("src/llvm-project").path("src/llvm-project/llvm")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -605,7 +605,7 @@ impl Step for Lld {
     const ONLY_HOSTS: bool = true;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/llvm-project/lld").path("src/tools/lld")
+        run.path("src/llvm-project/lld")
     }
 
     fn make_run(run: RunConfig<'_>) {
@@ -771,7 +771,7 @@ impl Step for Sanitizers {
     type Output = Vec<SanitizerRuntime>;
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("src/llvm-project/compiler-rt").path("src/sanitizers")
+        run.alias("sanitizers")
     }
 
     fn make_run(run: RunConfig<'_>) {
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index 39bcf4e8516..da468909811 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -2290,7 +2290,7 @@ impl Step for Distcheck {
     type Output = ();
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("distcheck")
+        run.alias("distcheck")
     }
 
     fn make_run(run: RunConfig<'_>) {
diff --git a/src/bootstrap/toolstate.rs b/src/bootstrap/toolstate.rs
index c7ea254c5b1..3ee6a42d987 100644
--- a/src/bootstrap/toolstate.rs
+++ b/src/bootstrap/toolstate.rs
@@ -234,7 +234,7 @@ impl Step for ToolStateCheck {
     }
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.path("check-tools")
+        run.alias("check-tools")
     }
 
     fn make_run(run: RunConfig<'_>) {