deb: retrieve only the artifacts produced by the build, not globbed files

build_binary_package_impl copied the whole parent directory into the
build root (ensure_available) and then retrieved every *.deb / *.changes
/ *.buildinfo it found there. That surfaced stale files already sitting
next to the package tree in the "Built in Ns:" summary.

Now local::build returns the exact set of artifacts produced by this
build — the binary packages registered in debian/files plus the
generated .buildinfo/.changes from generate_binary_metadata — and
build_binary_package_impl retrieves that list instead of globbing the
build root. Only files genuinely produced by the current build are
printed.

src/deb/local.rs

@@ -7,7 +7,7 @@ use crate::ui::logfmt::QuiltClassifier;
 use log::warn;
 use std::collections::HashMap;
 use std::error::Error;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 use crate::apt;
@@ -37,7 +37,8 @@ pub async fn build(
     inject_packages: Option<&[&str]>,
     ctx: Arc<Context>,
     ui: Option<Arc<DebUi>>,
-) -> Result<(), Box<dyn Error>> {
+    jobs: Option<usize>,
+) -> Result<Vec<PathBuf>, Box<dyn Error>> {
     let sink: Option<Arc<dyn LineSink>> = ui.as_ref().map(|u| u.sink());
 
     // Environment
@@ -45,21 +46,25 @@ pub async fn build(
     env.insert("LANG".to_string(), "C".to_string());
     env.insert("DEBIAN_FRONTEND".to_string(), "noninteractive".to_string());
 
-    // Parallel building: find local number of cores, and use that
-    let num_cores = ctx
-        .command("nproc")
-        .output()
-        .map(|output| {
-            if output.status.success() {
-                String::from_utf8_lossy(&output.stdout)
-                    .trim()
-                    .parse::<usize>()
-                    .unwrap_or(1)
-            } else {
-                1 // Default to 1 if nproc fails
-            }
-        })
-        .unwrap_or(1); // Default to 1 if we can't execute the command
+    // Parallel building: honor an explicit -j/--jobs count, otherwise detect
+    // the number of cores available inside the build context (nproc).
+    let num_cores = match jobs {
+        Some(j) => j,
+        None => ctx
+            .command("nproc")
+            .output()
+            .map(|output| {
+                if output.status.success() {
+                    String::from_utf8_lossy(&output.stdout)
+                        .trim()
+                        .parse::<usize>()
+                        .unwrap_or(1)
+                } else {
+                    1 // Default to 1 if nproc fails
+                }
+            })
+            .unwrap_or(1), // Default to 1 if we can't execute the command
+    };
 
     // Build options: parallel, disable tests by default
     env.insert(
@@ -329,15 +334,60 @@ pub async fn build(
         );
     }
 
+    // Collect the exact set of artifacts produced by this build so the caller
+    // retrieves only those: the binary packages registered in debian/files
+    // (the contract between dh_builddeb/dpkg-gencontrol and the artifact
+    // generators) plus the .buildinfo/.changes generated below. This avoids
+    // globbing the build root, which would also surface stale files copied
+    // alongside the package tree.
+    let mut artifacts = collect_binary_artifacts(&ctx, package_dir_str, build_root)?;
+
     // Generate the upload metadata (.buildinfo + .changes) natively, the
     // equivalent of dpkg-genbuildinfo -b + dpkg-genchanges -b, consuming
     // debian/files produced by the build. Failures are logged but do not
     // discard the produced binaries.
-    if let Err(e) = generate_upload_metadata(package_dir_str, build_root, arch, cross, &env, &ctx) {
-        warn!("failed to generate .buildinfo/.changes: {}", e);
+    match generate_upload_metadata(package_dir_str, build_root, arch, cross, &env, &ctx) {
+        Ok((buildinfo, changes)) => {
+            log::info!(
+                "generated upload metadata: {} and {}",
+                buildinfo.display(),
+                changes.display()
+            );
+            artifacts.push(buildinfo);
+            artifacts.push(changes);
+        }
+        Err(e) => {
+            warn!("failed to generate .buildinfo/.changes: {}", e);
+        }
     }
 
-    Ok(())
+    Ok(artifacts)
+}
+
+/// Collect the binary artifacts (.deb/.udeb) registered by the build in
+/// `debian/files`, returning their paths inside the build context
+/// (`<build_root>/<filename>`). `debian/files` is the canonical record of
+/// which binary packages `debian/rules binary` produced, so we retrieve
+/// exactly those instead of globbing the build root (which would also pick
+/// up stale files copied alongside the package tree).
+fn collect_binary_artifacts(
+    ctx: &Arc<Context>,
+    package_dir: &str,
+    build_root: &str,
+) -> Result<Vec<PathBuf>, Box<dyn Error>> {
+    let files_content = ctx
+        .read_file(&Path::new(package_dir).join("debian/files"))
+        .unwrap_or_default();
+    let files_list = crate::debian::FilesList::parse(&files_content)
+        .map_err(|e| format!("invalid debian/files in {package_dir}: {e}"))?;
+    let upload_dir = Path::new(build_root);
+    let mut artifacts = Vec::new();
+    for entry in files_list.iter() {
+        if matches!(entry.package_type.as_deref(), Some("deb") | Some("udeb")) {
+            artifacts.push(upload_dir.join(&entry.filename));
+        }
+    }
+    Ok(artifacts)
 }
 
 /// Generate `.buildinfo` and `.changes` for the finished binary build,
@@ -349,9 +399,7 @@ fn generate_upload_metadata(
     cross: bool,
     env: &HashMap<String, String>,
     ctx: &Arc<Context>,
-) -> Result<(), Box<dyn Error>> {
-    use std::path::Path;
-
+) -> Result<(PathBuf, PathBuf), Box<dyn Error>> {
     let changelog_path = Path::new(package_dir).join("debian/changelog");
     let changelog_content = ctx.read_file(&changelog_path)?;
     let entry = crate::debian::parse_changelog_entry_from_str(&changelog_content)?;
@@ -409,12 +457,7 @@ fn generate_upload_metadata(
         Path::new(build_root),
         &opts,
     )?;
-    log::info!(
-        "generated upload metadata: {} and {}",
-        buildinfo.display(),
-        changes.display()
-    );
-    Ok(())
+    Ok((buildinfo, changes))
 }
 
 /// Apply quilt patches before building, if the package provides a

src/deb/mod.rs

@@ -17,10 +17,13 @@ pub enum BuildMode {
 
 /// Build package in 'cwd' to a .deb
 ///
-/// Returns the list of produced .deb files retrieved locally. When `ui` is
+/// Returns the list of produced artifacts (.deb files plus the upload
+/// metadata `.buildinfo`/`.changes`) retrieved locally, identified from
+/// `debian/files` and the native metadata generation rather than by
+/// globbing the build root (which would surface stale files). When `ui` is
 /// set, a live view (status bar + rolling log pane) is displayed and all
-/// subprocess output is captured through it; on failure the widget is cleared
-/// and a summary of captured errors is printed.
+/// subprocess output is captured through it; on failure the widget is
+/// cleared and a summary of captured errors is printed.
 #[allow(clippy::too_many_arguments)]
 pub async fn build_binary_package(
     arch: Option<&str>,
@@ -33,6 +36,7 @@ pub async fn build_binary_package(
     inject_packages: Option<&[&str]>,
     ctx: Option<Arc<Context>>,
     ui: Option<Arc<DebUi>>,
+    jobs: Option<usize>,
 ) -> Result<Vec<PathBuf>, Box<dyn Error>> {
     let result = build_binary_package_impl(
         arch,
@@ -45,6 +49,7 @@ pub async fn build_binary_package(
         inject_packages,
         ctx,
         &ui,
+        jobs,
     )
     .await;
 
@@ -68,6 +73,7 @@ async fn build_binary_package_impl(
     inject_packages: Option<&[&str]>,
     ctx: Option<Arc<Context>>,
     ui: &Option<Arc<DebUi>>,
+    jobs: Option<usize>,
 ) -> Result<Vec<PathBuf>, Box<dyn Error>> {
     let cwd = cwd.unwrap_or_else(|| Path::new("."));
 
@@ -145,8 +151,11 @@ async fn build_binary_package_impl(
             .ok_or("Cannot find parent directory name")?;
         let build_root = format!("{}/{}", build_root, parent_dir_name.to_str().unwrap());
 
-        // Run the build using target build mode
-        match mode {
+        // Run the build using target build mode. It returns the exact set of
+        // artifacts produced by this build (binary packages registered in
+        // debian/files plus the generated .buildinfo/.changes), as paths
+        // inside the build context.
+        let remote_files: Vec<PathBuf> = match mode {
             BuildMode::Local => {
                 local::build(
                     &package,
@@ -160,33 +169,24 @@ async fn build_binary_package_impl(
                     inject_packages,
                     build_ctx.clone(),
                     ui.clone(),
+                    jobs,
                 )
                 .await?
             }
-        }
+        };
 
-        // Retrieve produced artifacts (.deb files plus the upload metadata
-        // (.buildinfo/.changes) generated natively after the build)
+        // Retrieve the produced artifacts (binary packages plus the upload
+        // metadata) to the parent directory.
         if let Some(u) = ui {
             u.phase(Phase::RetrievingArtifacts);
         }
-        let remote_files = build_ctx.list_files(Path::new(&build_root))?;
-        let deb_files: Vec<PathBuf> = remote_files
-            .into_iter()
-            .filter(|f| {
-                f.extension().is_some_and(|ext| {
-                    matches!(
-                        ext.to_str(),
-                        Some("deb") | Some("buildinfo") | Some("changes")
-                    )
-                })
-            })
-            .collect();
-        let total_debs = deb_files.len();
+        let total_debs = remote_files.len();
 
         let mut artifacts = Vec::with_capacity(total_debs);
-        for (idx, remote_file) in deb_files.iter().enumerate() {
-            let file_name = remote_file.file_name().ok_or("Invalid remote filename")?;
+        for (idx, remote_file) in remote_files.iter().enumerate() {
+            let file_name = remote_file
+                .file_name()
+                .ok_or("Invalid remote filename")?;
             let local_dest = parent_dir.join(file_name);
             build_ctx.retrieve_path(remote_file, &local_dest)?;
             artifacts.push(local_dest);
@@ -414,6 +414,7 @@ mod tests {
             None,
             Some(ctx),
             None,
+            None,
         )
         .await
         .expect("Cannot build binary package (deb)");

src/main.rs

@@ -78,6 +78,7 @@ fn main() {
                     .long_help("Cross-compile for target architecture (instead of using qemu-binfmt)\nNote that most packages cannot be cross-compiled").required(false))
                 .arg(arg!(--mode <mode> "Change build mode [local]").required(false)
                     .long_help("Change build mode [local]\nDefault will chose depending on other parameters, don't provide if unsure"))
+                .arg(arg!(-j --jobs <jobs> "Number of parallel build jobs (default: number of CPUs available in the build context)").required(false))
                 .arg(arg!(--verbose "Show raw tool output instead of the live build view").required(false)
                     .long_help("Show raw tool output instead of the live build view.\nAlso implied by RUST_LOG=debug for pkh's own logs.")),
         )
@@ -313,6 +314,14 @@ fn main() {
                 .copied()
                 .unwrap_or(false);
 
+            let jobs = sub_matches.get_one::<String>("jobs").map(|s| s.as_str());
+            let jobs = jobs.map(|j| {
+                j.parse::<usize>().unwrap_or_else(|_| {
+                    error!("Invalid --jobs value '{}': expected a positive integer", j);
+                    std::process::exit(1);
+                })
+            });
+
             // Live build view: disabled by --verbose or when stdout is not a
             // terminal (DebUi handles the non-TTY case itself)
             let ui = if verbose {
@@ -333,6 +342,7 @@ fn main() {
                     inject_packages,
                     None,
                     ui.clone(),
+                    jobs,
                 )
                 .await
             });