Add some help about rustup's +toolchain syntax.

src/bin/cargo/cli.rs

@@ -256,13 +256,20 @@ impl GlobalArgs {
 }
 
 fn cli() -> App {
+    let is_rustup = std::env::var_os("RUSTUP_HOME").is_some();
+    let usage = if is_rustup {
+        "cargo [+toolchain] [OPTIONS] [SUBCOMMAND]"
+    } else {
+        "cargo [OPTIONS] [SUBCOMMAND]"
+    };
     App::new("cargo")
         .settings(&[
             AppSettings::UnifiedHelpMessage,
             AppSettings::DeriveDisplayOrder,
             AppSettings::VersionlessSubcommands,
             AppSettings::AllowExternalSubcommands,
         ])
+        .usage(usage)
         .template(
             "\
 Rust's package manager

src/doc/man/generated/cargo-bench.html

@@ -419,6 +419,14 @@ <h3 id="cargo_bench_manifest_options">Manifest Options</h3>
 <h3 id="cargo_bench_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-build.html

@@ -350,6 +350,14 @@ <h3 id="cargo_build_manifest_options">Manifest Options</h3>
 <h3 id="cargo_build_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-check.html

@@ -341,6 +341,14 @@ <h3 id="cargo_check_manifest_options">Manifest Options</h3>
 <h3 id="cargo_check_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-clean.html

@@ -170,6 +170,14 @@ <h3 id="cargo_clean_manifest_options">Manifest Options</h3>
 <h3 id="cargo_clean_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-doc.html

@@ -311,6 +311,14 @@ <h3 id="cargo_doc_manifest_options">Manifest Options</h3>
 <h3 id="cargo_doc_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-fetch.html

@@ -147,6 +147,14 @@ <h3 id="cargo_fetch_manifest_options">Manifest Options</h3>
 <h3 id="cargo_fetch_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-fix.html

@@ -417,6 +417,14 @@ <h3 id="cargo_fix_manifest_options">Manifest Options</h3>
 <h3 id="cargo_fix_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-generate-lockfile.html

@@ -115,6 +115,14 @@ <h3 id="cargo_generate_lockfile_manifest_options">Manifest Options</h3>
 <h3 id="cargo_generate_lockfile_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-init.html

@@ -187,6 +187,14 @@ <h3 id="cargo_init_display_options">Display Options</h3>
 <h3 id="cargo_init_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-install.html

@@ -369,6 +369,14 @@ <h3 id="cargo_install_display_options">Display Options</h3>
 <h3 id="cargo_install_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-locate-project.html

@@ -84,6 +84,14 @@ <h3 id="cargo_locate_project_manifest_options">Manifest Options</h3>
 <h3 id="cargo_locate_project_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-login.html

@@ -92,6 +92,14 @@ <h3 id="cargo_login_display_options">Display Options</h3>
 <h3 id="cargo_login_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-metadata.html

@@ -441,6 +441,14 @@ <h3 id="cargo_metadata_manifest_options">Manifest Options</h3>
 <h3 id="cargo_metadata_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-new.html

@@ -180,6 +180,14 @@ <h3 id="cargo_new_display_options">Display Options</h3>
 <h3 id="cargo_new_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-owner.html

@@ -128,6 +128,14 @@ <h3 id="cargo_owner_display_options">Display Options</h3>
 <h3 id="cargo_owner_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-package.html

@@ -278,6 +278,14 @@ <h3 id="cargo_package_display_options">Display Options</h3>
 <h3 id="cargo_package_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-pkgid.html

@@ -174,6 +174,14 @@ <h3 id="cargo_pkgid_manifest_options">Manifest Options</h3>
 <h3 id="cargo_pkgid_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-publish.html

@@ -262,6 +262,14 @@ <h3 id="cargo_publish_display_options">Display Options</h3>
 <h3 id="cargo_publish_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-run.html

@@ -263,6 +263,14 @@ <h3 id="cargo_run_manifest_options">Manifest Options</h3>
 <h3 id="cargo_run_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-rustc.html

@@ -324,6 +324,14 @@ <h3 id="cargo_rustc_manifest_options">Manifest Options</h3>
 <h3 id="cargo_rustc_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-rustdoc.html

@@ -339,6 +339,14 @@ <h3 id="cargo_rustdoc_manifest_options">Manifest Options</h3>
 <h3 id="cargo_rustdoc_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-search.html

@@ -90,6 +90,14 @@ <h3 id="cargo_search_display_options">Display Options</h3>
 <h3 id="cargo_search_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-test.html

@@ -439,6 +439,14 @@ <h3 id="cargo_test_manifest_options">Manifest Options</h3>
 <h3 id="cargo_test_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-tree.html

@@ -335,6 +335,14 @@ <h3 id="cargo_tree_display_options">Display Options</h3>
 <h3 id="cargo_tree_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>

src/doc/man/generated/cargo-uninstall.html

@@ -115,6 +115,14 @@ <h3 id="cargo_uninstall_display_options">Display Options</h3>
 <h3 id="cargo_uninstall_common_options">Common Options</h3>
 <div class="dlist">
 <dl>
+<dt class="hdlist1"><strong>+TOOLCHAIN</strong></dt>
+<dd>
+<p>If Cargo has been installed with rustup, and the first argument to <code>cargo</code>
+begins with <code>+</code>, it will be interpreted as a rustup toolchain name (such
+as <code>+stable</code> or <code>+nightly</code>).
+See the <a href="https://github.com/rust-lang/rustup/">rustup documentation</a>
+for more information about how toolchain overrides work.</p>
+</dd>
 <dt class="hdlist1"><strong>-h</strong></dt>
 <dt class="hdlist1"><strong>--help</strong></dt>
 <dd>