Auto merge of #62549 - ehuss:update-cargo-vendor, r=alexcrichton

Update cargo-vendor usage

This contains a variety of updates to clean up the usage of cargo-vendor.

- Remove the install step for the old cargo-vendor now that it is built-in to cargo and available in the stage0 install.
- Update installation instructions, dealing with vendoring. The current instructions of running `sudo ./x.py install` is broken, it will almost always fail (since the vendor directory doesn't exist). Since the steps for properly handling this are numerous, I'm recommending removing the suggestion to use `sudo` altogether.
- If the sudo-forced-vendoring detects that the vendor directory is not available, abort with instructions on how to fix.
- Now that cargo-vendor is built-in, automatically run it if it looks like it is needed.
- Update instructions on how to install cargo.
- Remove the unused markdown link references in README/CONTRIBUTING. This reverts most of #44935. These references don't do anything if they are unused.

Closes #49269
cc #61142 #48771 #40108

src/bootstrap/bootstrap.py

@@ -735,6 +735,47 @@ class RustBuild(object):
         """Set download URL for development environment"""
         self._download_url = 'https://dev-static.rust-lang.org'
 
+    def check_vendored_status(self):
+        """Check that vendoring is configured properly"""
+        vendor_dir = os.path.join(self.rust_root, 'vendor')
+        if 'SUDO_USER' in os.environ and not self.use_vendored_sources:
+            if os.environ.get('USER') != os.environ['SUDO_USER']:
+                self.use_vendored_sources = True
+                print('info: looks like you are running this command under `sudo`')
+                print('      and so in order to preserve your $HOME this will now')
+                print('      use vendored sources by default.')
+                if not os.path.exists(vendor_dir):
+                    print('error: vendoring required, but vendor directory does not exist.')
+                    print('       Run `cargo vendor` without sudo to initialize the '
+                        'vendor directory.')
+                    raise Exception("{} not found".format(vendor_dir))
+
+        if self.use_vendored_sources:
+            if not os.path.exists('.cargo'):
+                os.makedirs('.cargo')
+            with output('.cargo/config') as cargo_config:
+                cargo_config.write(
+                    "[source.crates-io]\n"
+                    "replace-with = 'vendored-sources'\n"
+                    "registry = 'https://example.com'\n"
+                    "\n"
+                    "[source.vendored-sources]\n"
+                    "directory = '{}/vendor'\n"
+                .format(self.rust_root))
+        else:
+            if os.path.exists('.cargo'):
+                shutil.rmtree('.cargo')
+
+    def ensure_vendored(self):
+        """Ensure that the vendored sources are available if needed"""
+        vendor_dir = os.path.join(self.rust_root, 'vendor')
+        # Note that this does not handle updating the vendored dependencies if
+        # the rust git repository is updated. Normal development usually does
+        # not use vendoring, so hopefully this isn't too much of a problem.
+        if self.use_vendored_sources and not os.path.exists(vendor_dir):
+            run([self.cargo(), "vendor"],
+                verbose=self.verbose, cwd=self.rust_root)
+
 
 def bootstrap(help_triggered):
     """Configure, fetch, build and run the initial bootstrap"""
@@ -776,30 +817,7 @@ def bootstrap(help_triggered):
 
     build.use_locked_deps = '\nlocked-deps = true' in build.config_toml
 
-    if 'SUDO_USER' in os.environ and not build.use_vendored_sources:
-        if os.environ.get('USER') != os.environ['SUDO_USER']:
-            build.use_vendored_sources = True
-            print('info: looks like you are running this command under `sudo`')
-            print('      and so in order to preserve your $HOME this will now')
-            print('      use vendored sources by default. Note that if this')
-            print('      does not work you should run a normal build first')
-            print('      before running a command like `sudo ./x.py install`')
-
-    if build.use_vendored_sources:
-        if not os.path.exists('.cargo'):
-            os.makedirs('.cargo')
-        with output('.cargo/config') as cargo_config:
-            cargo_config.write("""
-                [source.crates-io]
-                replace-with = 'vendored-sources'
-                registry = 'https://example.com'
-
-                [source.vendored-sources]
-                directory = '{}/vendor'
-            """.format(build.rust_root))
-    else:
-        if os.path.exists('.cargo'):
-            shutil.rmtree('.cargo')
+    build.check_vendored_status()
 
     data = stage0_data(build.rust_root)
     build.date = data['date']
@@ -815,6 +833,7 @@ def bootstrap(help_triggered):
     build.build = args.build or build.build_triple()
     build.download_stage0()
     sys.stdout.flush()
+    build.ensure_vendored()
     build.build_bootstrap()
     sys.stdout.flush()
 

src/bootstrap/dist.rs

@@ -935,8 +935,6 @@ impl Step for Src {
     }
 }
 
-const CARGO_VENDOR_VERSION: &str = "0.1.22";
-
 #[derive(Debug, PartialOrd, Ord, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct PlainSourceTarball;
 
@@ -998,26 +996,6 @@ impl Step for PlainSourceTarball {
 
         // If we're building from git sources, we need to vendor a complete distribution.
         if builder.rust_info.is_git() {
-            // Get cargo-vendor installed, if it isn't already.
-            let mut has_cargo_vendor = false;
-            let mut cmd = Command::new(&builder.initial_cargo);
-            for line in output(cmd.arg("install").arg("--list")).lines() {
-                has_cargo_vendor |= line.starts_with("cargo-vendor ");
-            }
-            if !has_cargo_vendor {
-                let mut cmd = builder.cargo(
-                    builder.compiler(0, builder.config.build),
-                    Mode::ToolBootstrap,
-                    builder.config.build,
-                    "install"
-                );
-                cmd.arg("--force")
-                   .arg("--debug")
-                   .arg("--vers").arg(CARGO_VENDOR_VERSION)
-                   .arg("cargo-vendor");
-                builder.run(&mut cmd);
-            }
-
             // Vendor all Cargo dependencies
             let mut cmd = Command::new(&builder.initial_cargo);
             cmd.arg("vendor")