Give a better error message if a component is not installed

Author: nrc

src/rustup-cli/self_update.rs

@@ -34,6 +34,7 @@ use common::{self, Confirm};
 use errors::*;
 use rustup_dist::dist;
 use rustup_utils::utils;
+use rustup::{TOOLS, DUP_TOOLS};
 use same_file::Handle;
 use std::env;
 use std::env::consts::EXE_SUFFIX;
@@ -192,14 +193,6 @@ doing then it is fine to continue installation without the build
 tools, but otherwise, install the C++ build tools before proceeding.
 "#;
 
-static TOOLS: &'static [&'static str] =
-    &["rustc", "rustdoc", "cargo", "rust-lldb", "rust-gdb", "rls", "cargo-clippy"];
-
-// Tools which are commonly installed by Cargo as well as rustup. We take a bit
-// more care with these to ensure we don't overwrite the user's previous
-// installation.
-static DUP_TOOLS: &'static [&'static str] = &["rustfmt", "cargo-fmt"];
-
 static UPDATE_ROOT: &'static str = "https://static.rust-lang.org/rustup";
 
 /// `CARGO_HOME` suitable for display, possibly with $HOME

src/rustup/errors.rs

@@ -1,5 +1,6 @@
 use rustup_dist::{self, temp};
 use rustup_utils;
+use component_for_bin;
 use toml;
 
 error_chain! {
@@ -27,7 +28,7 @@ error_chain! {
         }
         BinaryNotFound(t: String, bin: String) {
             description("toolchain does not contain binary")
-            display("toolchain '{}' does not have the binary `{}`", t, bin)
+            display("'{}' is not installed for the toolchain '{}'{}", bin, t, install_msg(bin))
         }
         NeedMetadataUpgrade {
             description("rustup's metadata is out of date. run `rustup self upgrade-data`")
@@ -71,3 +72,10 @@ error_chain! {
         }
     }
 }
+
+fn install_msg(bin: &str) -> String {
+    match component_for_bin(bin) {
+        Some(c) => format!("\nTo install, run `rustup component add {}`", c),
+        None => String::new(),
+    }
+}

src/rustup/lib.rs

@@ -22,6 +22,29 @@ pub use config::*;
 pub use toolchain::*;
 pub use rustup_utils::{notify, toml_utils, utils};
 
+
+// A list of all binaries which Rustup will proxy.
+pub static TOOLS: &'static [&'static str] =
+    &["rustc", "rustdoc", "cargo", "rust-lldb", "rust-gdb", "rls", "cargo-clippy"];
+
+// Tools which are commonly installed by Cargo as well as rustup. We take a bit
+// more care with these to ensure we don't overwrite the user's previous
+// installation.
+pub static DUP_TOOLS: &'static [&'static str] = &["rustfmt", "cargo-fmt"];
+
+fn component_for_bin(binary: &str) -> Option<&'static str> {
+    match binary {
+        "rustc" | "rustdoc" => Some("rustc"),
+        "cargo" => Some("cargo"),
+        "rust-lldb" => Some("lldb-preview"),
+        "rust-gdb" => Some("gdb-preview"),
+        "rls" => Some("rls"),
+        "cargo-clippy" => Some("clippy"),
+        "rustfmt" | "cargo-fmt" => Some("rustfmt"),
+        _ => None,
+    }
+}
+
 mod errors;
 mod notifications;
 mod toolchain;

tests/cli-misc.rs

@@ -377,7 +377,7 @@ fn rustup_failed_path_search() {
             config,
             broken,
             &format!(
-                "toolchain 'custom' does not have the binary `fake_proxy{}`",
+                "'fake_proxy{}' is not installed for the toolchain 'custom'",
                 EXE_SUFFIX
             ),
         );
@@ -550,9 +550,9 @@ fn rls_does_not_exist_in_toolchain() {
             config,
             &["rls", "--version"],
             &format!(
-                "toolchain 'stable-{}' does not have the binary `rls{}`",
+                "'rls{}' is not installed for the toolchain 'stable-{}'",
+                EXE_SUFFIX,
                 this_host_triple(),
-                EXE_SUFFIX
             ),
         );
     });
@@ -659,12 +659,12 @@ fn rename_rls_remove() {
         expect_ok(config, &["rustup", "component", "add", "rls"]);
         expect_ok(config, &["rls", "--version"]);
         expect_ok(config, &["rustup", "component", "remove", "rls"]);
-        expect_err(config, &["rls", "--version"], "does not have the binary `rls`");
+        expect_err(config, &["rls", "--version"], "'rls' is not installed");
 
         expect_ok(config, &["rustup", "component", "add", "rls"]);
         expect_ok(config, &["rls", "--version"]);
         expect_ok(config, &["rustup", "component", "remove", "rls-preview"]);
-        expect_err(config, &["rls", "--version"], "does not have the binary `rls`");
+        expect_err(config, &["rls", "--version"], "'rls' is not installed");
     });
 }
 

tests/cli-self-upd.rs

@@ -1306,9 +1306,9 @@ fn rls_proxy_set_up_after_install() {
             config,
             &["rls", "--version"],
             &format!(
-                "toolchain 'stable-{}' does not have the binary `rls{}`",
+                "'rls{}' is not installed for the toolchain 'stable-{}'",
+                EXE_SUFFIX,
                 this_host_triple(),
-                EXE_SUFFIX
             ),
         );
         expect_ok(config, &["rustup", "component", "add", "rls"]);