Give a better error message when the CI download fails

Author: Teapot4195

src/bootstrap/src/core/download.rs

@@ -6,6 +6,7 @@ use std::{
     path::{Path, PathBuf},
     process::{Command, Stdio},
     sync::OnceLock,
+    time::SystemTime,
 };
 
 use build_helper::ci::CiEnv;
@@ -194,7 +195,7 @@ impl Config {
         let _ = try_run(self, patchelf.arg(fname));
     }
 
-    fn download_file(&self, url: &str, dest_path: &Path, help_on_error: &str) {
+    fn download_file(&self, url: &str, dest_path: &Path, help_on_error: &str, commit: &String) {
         self.verbose(&format!("download {url}"));
         // Use a temporary file in case we crash while downloading, to avoid a corrupt download in cache/.
         let tempfile = self.tempdir().join(dest_path.file_name().unwrap());
@@ -203,7 +204,7 @@ impl Config {
         // protocols without worrying about merge conflicts if we change the HTTP implementation.
         match url.split_once("://").map(|(proto, _)| proto) {
             Some("http") | Some("https") => {
-                self.download_http_with_retries(&tempfile, url, help_on_error)
+                self.download_http_with_retries(&tempfile, url, help_on_error, commit)
             }
             Some(other) => panic!("unsupported protocol {other} in {url}"),
             None => panic!("no protocol in {url}"),
@@ -214,7 +215,13 @@ impl Config {
         );
     }
 
-    fn download_http_with_retries(&self, tempfile: &Path, url: &str, help_on_error: &str) {
+    fn download_http_with_retries(
+        &self,
+        tempfile: &Path,
+        url: &str,
+        help_on_error: &str,
+        commit: &String,
+    ) {
         println!("downloading {url}");
         // Try curl. If that fails and we are on windows, fallback to PowerShell.
         let mut curl = Command::new("curl");
@@ -250,19 +257,70 @@ impl Config {
                             "(New-Object System.Net.WebClient).DownloadFile('{}', '{}')",
                             url, tempfile.to_str().expect("invalid UTF-8 not supported with powershell downloads"),
                         ),
-                    ])).is_err() {
+                    ])).is_ok() {
                         return;
                     }
                     eprintln!("\nspurious failure, trying again");
                 }
             }
             if !help_on_error.is_empty() {
                 eprintln!("{help_on_error}");
+                Self::check_outdated(commit);
             }
             crate::exit!(1);
         }
     }
 
+    fn check_outdated(commit: &String) {
+        let last_commit: String = String::from_utf8(
+            Command::new("git")
+                .arg("show")
+                .arg("-s")
+                .arg("--date=short")
+                .arg("--format=%ct")
+                .arg("HEAD")
+                .output()
+                .expect("Failed to get git log")
+                .stdout,
+        )
+        .unwrap_or("".to_string());
+        match SystemTime::now().duration_since(SystemTime::UNIX_EPOCH) {
+            Ok(n) => {
+                let replaced = last_commit.replace("\n", "");
+                let diff = n.as_secs() - replaced.parse::<u64>().unwrap();
+                if diff >= 165 * 24 * 60 * 60 {
+                    // HEAD is more than 165 days out of date
+                    eprintln!(
+                        "NOTE: HEAD is {} days out of date, CI builds disappear in 168 days.",
+                        diff / (24 * 60 * 60)
+                    );
+                    let build_date: String = String::from_utf8(
+                        Command::new("git")
+                            .arg("show")
+                            .arg("-s")
+                            .arg("--format=%ar")
+                            .arg(commit)
+                            .output()
+                            .unwrap()
+                            .stdout,
+                    )
+                    .unwrap_or("".to_string());
+                    if build_date.is_empty() {
+                        eprintln!("NOTE: tried to download builds for {}", commit);
+                    } else {
+                        eprintln!(
+                            "NOTE: tried to download builds for {} (from {})",
+                            commit, build_date
+                        );
+                    }
+                    eprintln!("HELP: Consider updating your copy of the rust sources");
+                    return;
+                }
+            }
+            Err(_) => panic!("SystemTime before UNIX EPOCH!"),
+        }
+    }
+
     fn unpack(&self, tarball: &Path, dst: &Path, pattern: &str) {
         eprintln!("extracting {} to {}", tarball.display(), dst.display());
         if !dst.exists() {
@@ -492,7 +550,7 @@ impl Config {
         let extra_components = ["cargo"];
 
         let download_beta_component = |config: &Config, filename, prefix: &_, date: &_| {
-            config.download_component(DownloadSource::Dist, filename, prefix, date, "stage0")
+            config.download_component(DownloadSource::Dist, filename, prefix, date, "stage0");
         };
 
         self.download_toolchain(
@@ -648,7 +706,7 @@ HELP: if trying to compile an old commit of rustc, disable `download-rustc` in c
 download-rustc = false
 ";
         }
-        self.download_file(&format!("{base_url}/{url}"), &tarball, help_on_error);
+        self.download_file(&format!("{base_url}/{url}"), &tarball, help_on_error, &key.to_string());
         if let Some(sha256) = checksum {
             if !self.verify(&tarball, sha256) {
                 panic!("failed to verify {}", tarball.display());
@@ -726,7 +784,12 @@ download-rustc = false
     [llvm]
     download-ci-llvm = false
     ";
-            self.download_file(&format!("{base}/{llvm_sha}/{filename}"), &tarball, help_on_error);
+            self.download_file(
+                &format!("{base}/{llvm_sha}/{filename}"),
+                &tarball,
+                help_on_error,
+                &llvm_sha.to_string(),
+            );
         }
         let llvm_root = self.ci_llvm_root();
         self.unpack(&tarball, &llvm_root, "rust-dev");