pull: fix hang caused by blocking git2 call and redundant Launchpad checks

src/package_info.rs

@@ -19,7 +19,7 @@ pub fn ppa_to_base_url(user: &str, name: &str) -> String {
     format!("http://ppa.launchpadcontent.net/{}/{}/ubuntu", user, name)
 }
 
-async fn check_launchpad_repo(package: &str) -> Result<Option<String>, Box<dyn Error>> {
+fn check_launchpad_repo_sync(package: &str) -> Result<Option<String>, String> {
     let url = format!("https://git.launchpad.net/ubuntu/+source/{}", package);
 
     // Use libgit2 to check if the remote repository exists
@@ -33,6 +33,31 @@ async fn check_launchpad_repo(package: &str) -> Result<Option<String>, Box<dyn E
     }
 }
 
+/// Check if a Launchpad git repository exists for the given package.
+///
+/// This runs the blocking git2 connection check on a dedicated thread with a
+/// timeout so that it never stalls the tokio runtime (the git2 connect call
+/// has no built-in timeout and can hang for minutes on unreachable hosts).
+async fn check_launchpad_repo(
+    package: &str,
+) -> Result<Option<String>, Box<dyn Error + Send + Sync>> {
+    let package_owned = package.to_string();
+    let package_for_err = package_owned.clone();
+    let result = tokio::time::timeout(
+        std::time::Duration::from_secs(15),
+        tokio::task::spawn_blocking(move || check_launchpad_repo_sync(&package_owned)),
+    )
+    .await
+    .map_err(|_| {
+        format!(
+            "Timed out checking Launchpad repository for '{}'",
+            package_for_err
+        )
+    })?
+    .map_err(|e| format!("Launchpad check task failed: {}", e))?;
+    result.map_err(|e| -> Box<dyn Error + Send + Sync> { e.into() })
+}
+
 /// A File used in a source package
 #[derive(Debug, Clone)]
 pub struct FileEntry {
@@ -245,24 +270,24 @@ fn parse_sources(
 }
 
 /// Get package information from a package, distribution series, and pocket
+///
+/// `launchpad_vcs` is a pre-computed Launchpad VCS URL (if any), checked once
+/// by the caller so that the blocking git2 connection test is not repeated for
+/// every series/pocket combination.
 async fn get(
     package_name: &str,
     series: &str,
     pocket: &str,
     version: Option<&str>,
     base_url: Option<&str>,
+    launchpad_vcs: Option<String>,
 ) -> Result<PackageInfo, Box<dyn Error>> {
     let dist = crate::distro_info::get_dist_from_series(series).await?;
 
-    // Handle Ubuntu case: Vcs-Git does not usually point to Launchpad but Salsa
+    // Use the pre-computed Launchpad VCS URL (if any).
-    // We need to check manually if there is a launchpad repository for the package
+    // This is checked once in the caller rather than per-series to avoid
-    let mut preferred_vcs = None;
+    // repeated blocking git2 connections.
-    if dist == "ubuntu"
+    let mut preferred_vcs = launchpad_vcs;
-        && let Some(lp_url) = check_launchpad_repo(package_name).await?
-    {
-        debug!("Found Launchpad URL: {}", lp_url);
-        preferred_vcs = Some(lp_url);
-    }
 
     // Determine the base URL to use (either provided PPA URL or default archive)
     let distro_base_url = crate::distro_info::get_base_url(&dist)?;
@@ -340,6 +365,7 @@ async fn find_package(
     pocket: &str,
     version: Option<&str>,
     base_url: Option<&str>,
+    launchpad_vcs: Option<String>,
     progress: ProgressCallback<'_>,
 ) -> Result<PackageInfo, Box<dyn Error>> {
     let series_list = crate::distro_info::get_ordered_series_name(dist).await?;
@@ -356,7 +382,16 @@ async fn find_package(
         };
 
         for p in pockets {
-            match get(package_name, series, &p, version, base_url).await {
+            match get(
+                package_name,
+                series,
+                &p,
+                version,
+                base_url,
+                launchpad_vcs.clone(),
+            )
+            .await
+            {
                 Ok(info) => {
                     if i > 0 {
                         let location = if p.is_empty() {
@@ -410,6 +445,41 @@ pub async fn lookup(
     base_url: Option<&str>,
     progress: ProgressCallback<'_>,
 ) -> Result<PackageInfo, Box<dyn Error>> {
+    // Resolve the distribution early so we can check Launchpad once
+    let resolved_dist = dist.unwrap_or_else(||
+        // Use auto-detection to see if current distro is ubuntu, or fallback to debian by default
+        if std::process::Command::new("lsb_release").arg("-i").arg("-s").output()
+            .map(|o| String::from_utf8_lossy(&o.stdout).trim().to_lowercase()).unwrap_or_default() == "ubuntu" {
+            "ubuntu"
+        } else {
+            "debian"
+        }
+    );
+
+    // Check Launchpad repository once for Ubuntu packages, rather than
+    // once per series/pocket combination inside get().
+    let launchpad_vcs = if resolved_dist == "ubuntu" && base_url.is_none() {
+        if let Some(cb) = progress {
+            cb("", &format!("Checking Launchpad for {}...", package), 0, 0);
+        }
+        match check_launchpad_repo(package).await {
+            Ok(Some(lp_url)) => {
+                debug!("Found Launchpad URL: {}", lp_url);
+                Some(lp_url)
+            }
+            Ok(None) => None,
+            Err(e) => {
+                debug!(
+                    "Launchpad check failed (will use stanza Vcs-Git if available): {}",
+                    e
+                );
+                None
+            }
+        }
+    } else {
+        None
+    };
+
     // Obtain the package information, either directly in a series or with a search in all series
     let package_info = if let Some(s) = series {
         if let Some(cb) = progress {
@@ -422,24 +492,18 @@ pub async fn lookup(
         }
 
         // Get the package information from that series and pocket
-        get(package, s, pocket, version, base_url).await?
+        get(package, s, pocket, version, base_url, launchpad_vcs).await?
     } else {
-        let dist = dist.unwrap_or_else(||
-            // Use auto-detection to see if current distro is ubuntu, or fallback to debian by default
-            if std::process::Command::new("lsb_release").arg("-i").arg("-s").output()
-                .map(|o| String::from_utf8_lossy(&o.stdout).trim().to_lowercase()).unwrap_or_default() == "ubuntu" {
-                "ubuntu"
-            } else {
-                "debian"
-            }
-        );
-
         if let Some(cb) = progress {
             cb(
                 &format!(
                     "Searching for package {} in {}...",
                     package,
-                    if base_url.is_none() { dist } else { "ppa" }
+                    if base_url.is_none() {
+                        resolved_dist
+                    } else {
+                        "ppa"
+                    }
                 ),
                 "",
                 0,
@@ -448,7 +512,16 @@ pub async fn lookup(
         }
 
         // Try to find the package in all series from that dist
-        find_package(package, dist, pocket, version, base_url, progress).await?
+        find_package(
+            package,
+            resolved_dist,
+            pocket,
+            version,
+            base_url,
+            launchpad_vcs,
+            progress,
+        )
+        .await?
     };
 
     Ok(package_info)
@@ -512,7 +585,7 @@ Version: 1.0
     #[tokio::test]
     async fn test_find_package_fallback() {
         // python2.7 is in bullseye but not above
-        let info = find_package("python2.7", "debian", "", None, None, None)
+        let info = find_package("python2.7", "debian", "", None, None, None, None)
             .await
             .unwrap();
         assert_eq!(info.stanza.package, "python2.7");
@@ -522,7 +595,7 @@ Version: 1.0
     #[tokio::test]
     async fn test_find_package_devel() {
         // hello is in sid
-        let info = find_package("hello", "debian", "", None, None, None)
+        let info = find_package("hello", "debian", "", None, None, None, None)
             .await
             .unwrap();
         assert_eq!(info.stanza.package, "hello");