Windows: Improve handling of Visual Studio errors

src/cli/self_update.rs

@@ -57,7 +57,7 @@ use anyhow::{anyhow, Context, Result};
 use cfg_if::cfg_if;
 use same_file::Handle;
 
-use super::common::{self, ignorable_error, Confirm};
+use super::common::{self, ignorable_error, report_error, Confirm};
 use super::errors::*;
 use super::markdown::md;
 use super::term2;
@@ -380,7 +380,22 @@ pub(crate) fn install(
                 "\nAutomatically download and install Visual Studio 2022 Community edition? (Y/n)",
                 true,
             )? {
-                try_install_msvc()?;
+                match try_install_msvc(&opts) {
+                    Err(e) => {
+                        // Make sure the console doesn't exit before the user can
+                        // see the error and give the option to continue anyway.
+                        report_error(&e);
+                        if !common::confirm("\nContinue installing rustup? (y/N)", false)? {
+                            info!("aborting installation");
+                            return Ok(utils::ExitCode(0));
+                        }
+                    }
+                    Ok(ContinueInstall::No) => {
+                        ensure_prompt()?;
+                        return Ok(utils::ExitCode(0));
+                    }
+                    _ => {}
+                }
             } else {
                 md(&mut term, MSVC_MANUAL_INSTALL_MESSAGE);
                 if !common::confirm("\nContinue? (y/N)", false)? {

src/cli/self_update/windows.rs

@@ -66,7 +66,7 @@ pub(crate) fn do_msvc_check(opts: &InstallOpts<'_>) -> Option<VsInstallPlan> {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Eq, PartialEq)]
 struct VsInstallError(i32);
 impl std::error::Error for VsInstallError {}
 impl fmt::Display for VsInstallError {
@@ -97,8 +97,21 @@ impl fmt::Display for VsInstallError {
         write!(f, "{} (exit code {})", message, self.0)
     }
 }
+impl VsInstallError {
+    const REBOOTING_NOW: Self = Self(1641);
+    const REBOOT_REQUIRED: Self = Self(3010);
+}
+
+pub(crate) enum ContinueInstall {
+    Yes,
+    No,
+}
 
-pub(crate) fn try_install_msvc() -> Result<()> {
+/// Tries to install the needed Visual Studio components.
+///
+/// Returns `Ok(ContinueInstall::No)` if installing Visual Studio was successful
+/// but the rustup install should not be continued at this time.
+pub(crate) fn try_install_msvc(opts: &InstallOpts<'_>) -> Result<ContinueInstall> {
     // download the installer
     let visual_studio_url = utils::parse_url("https://aka.ms/vs/17/release/vs_community.exe")?;
 
@@ -131,16 +144,7 @@ pub(crate) fn try_install_msvc() -> Result<()> {
 
     // It's possible an earlier or later version of the Windows SDK has been
     // installed separately from Visual Studio so installing it can be skipped.
-    let mut has_libs = false;
-    if let Some(paths) = process().var_os("lib") {
-        for mut path in split_paths(&paths) {
-            path.push("kernel32.lib");
-            if path.exists() {
-                has_libs = true;
-            }
-        }
-    };
-    if !has_libs {
+    if !has_windows_sdk_libs() {
         cmd.args([
             "--add",
             "Microsoft.VisualStudio.Component.Windows11SDK.22000",
@@ -154,12 +158,51 @@ pub(crate) fn try_install_msvc() -> Result<()> {
         .context("error running Visual Studio installer")?;
 
     if exit_status.success() {
-        Ok(())
+        Ok(ContinueInstall::Yes)
     } else {
-        Err(VsInstallError(exit_status.code().unwrap())).context("failed to install Visual Studio")
+        match VsInstallError(exit_status.code().unwrap()) {
+            err @ VsInstallError::REBOOT_REQUIRED => {
+                // A reboot is required but the user opted to delay it.
+                warn!("{}", err);
+                Ok(ContinueInstall::Yes)
+            }
+            err @ VsInstallError::REBOOTING_NOW => {
+                // The user is wanting to reboot right now, so we should
+                // not continue the install.
+                warn!("{}", err);
+                info!("\nRun rustup-init after restart to continue install");
+                Ok(ContinueInstall::No)
+            }
+            err => {
+                // It's possible that the installer returned a non-zero exit code
+                // even though the required components were successfully installed.
+                // In that case we warn about the error but continue on.
+                let have_msvc = do_msvc_check(opts).is_none();
+                let has_libs = has_windows_sdk_libs();
+                if have_msvc && has_libs {
+                    warn!("Visual Studio is installed but a problem ocurred during installation");
+                    warn!("{}", err);
+                    Ok(ContinueInstall::Yes)
+                } else {
+                    Err(err).context("failed to install Visual Studio")
+                }
+            }
+        }
     }
 }
 
+fn has_windows_sdk_libs() -> bool {
+    if let Some(paths) = process().var_os("lib") {
+        for mut path in split_paths(&paths) {
+            path.push("kernel32.lib");
+            if path.exists() {
+                return true;
+            }
+        }
+    };
+    false
+}
+
 /// Run by rustup-gc-$num.exe to delete CARGO_HOME
 pub fn complete_windows_uninstall() -> Result<utils::ExitCode> {
     use std::process::Stdio;