feat(rustup_mode): revise help message

to suggest command to install missing components. make them more
consistent.

Author: Bogay

src/cli/rustup_mode.rs

@@ -1045,7 +1045,7 @@ async fn which(
     };
 
     Err(anyhow!(
-        "'{binary}' is not installed for the toolchain '{toolchain_name}'.\nTo install, run `rustup component add {selector}{component_name}`"
+        "'{binary}' is not installed for the toolchain '{toolchain_name}'.\nhelp: run `rustup component add {selector}{component_name}` to install it"
     ))
 }
 
@@ -1714,11 +1714,8 @@ async fn doc(
             .as_slice()
     {
         info!(
-            "`rust-docs` not installed in toolchain `{}`",
-            distributable.desc()
-        );
-        info!(
-            "To install, try `rustup component add --toolchain {} rust-docs`",
+            "`rust-docs` not installed in toolchain `{}`\nhelp: run `rustup component add --toolchain {} rust-docs` to install it",
+            distributable.desc(),
             distributable.desc()
         );
         return Err(anyhow!(

src/toolchain/distributable.rs

@@ -453,7 +453,7 @@ impl<'a> DistributableToolchain<'a> {
                     _ => format!("--toolchain {} ", self.toolchain.name()),
                 };
                 Err(anyhow!(
-                    "'{binary_lossy}' is not installed for the toolchain '{desc}'.\nTo install, run `rustup component add {selector}{component_name}`"
+                    "'{binary_lossy}' is not installed for the toolchain '{desc}'.\nhelp: run `rustup component add {selector}{component_name}` to install it"
                 ))
             }
         } else {

tests/suite/cli_misc.rs

@@ -711,7 +711,7 @@ async fn run_rls_when_not_installed() {
         .await
         .with_stderr(snapbox::str![[r#"
 error: 'rls[EXE]' is not installed for the toolchain 'stable-[HOST_TRIPLE]'.
-To install, run `rustup component add rls`
+help: run `rustup component add rls` to install it
 
 "#]])
         .is_err();
@@ -733,7 +733,7 @@ async fn run_rls_when_not_installed_for_nightly() {
         .await
         .with_stderr(snapbox::str![[r#"
 error: 'rls[EXE]' is not installed for the toolchain 'nightly-[HOST_TRIPLE]'.
-To install, run `rustup component add --toolchain nightly-[HOST_TRIPLE] rls`
+help: run `rustup component add --toolchain nightly-[HOST_TRIPLE] rls` to install it
 
 "#]])
         .is_err();
@@ -1409,7 +1409,7 @@ async fn which_asking_uninstalled_components() {
         .await
         .with_stderr(snapbox::str![[r#"
 error: 'rustfmt' is not installed for the toolchain 'custom-1'.
-[..]`rustup component add rustfmt`
+[..]`rustup component add rustfmt`[..]
 
 "#]])
         .is_err();
@@ -1425,7 +1425,7 @@ error: 'rustfmt' is not installed for the toolchain 'custom-1'.
         .await
         .with_stderr(snapbox::str![[r#"
 [..]'rustfmt' is not installed for the toolchain 'custom-2'.
-[..]`rustup component add --toolchain custom-2 rustfmt`
+[..]`rustup component add --toolchain custom-2 rustfmt`[..]
 
 "#]])
         .is_err();

tests/suite/cli_rustup.rs

@@ -3373,7 +3373,7 @@ async fn docs_missing() {
         .await
         .with_stderr(snapbox::str![[r#"
 info: `rust-docs` not installed in toolchain `nightly-[HOST_TRIPLE]`
-info: To install, try `rustup component add --toolchain nightly-[HOST_TRIPLE] rust-docs`
+help: run `rustup component add --toolchain nightly-[HOST_TRIPLE] rust-docs` to install it
 error: unable to view documentation which is not installed
 
 "#]])

tests/suite/cli_self_upd.rs

@@ -1008,7 +1008,7 @@ async fn rls_proxy_set_up_after_install() {
         .await
         .with_stderr(snapbox::str![[r#"
 error: 'rls[EXE]' is not installed for the toolchain 'stable-[HOST_TRIPLE]'.
-To install, run `rustup component add rls`
+help: run `rustup component add rls` to install it
 
 "#]])
         .is_err();