scripts: Add build-deb to build a Debian package

Expects a yaml file such as:

dsc_url: "https://snapshot.debian.org/archive/debian/20250416T143525Z/pool/main/h/hello/hello_2.10-5.dsc"
dsc_sha256sum: "319f8c377eb48597798b699f72ab853f3439a991583ddd51bf94b415373ffdfe"
debdiff_file: "hello_2.10-5qcom1.debdiff"
suite: "trixie"

Signed-off-by: Loïc Minier <[email protected]>

Author: lool

scripts/build-deb.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+# Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+# SPDX-License-Identifier: BSD-3-Clause
+
+# Build a Debian package using sbuild; input is a yaml configuration
+# with base dsc URL, debdiff file to apply and target series
+
+import argparse
+import glob
+import hashlib
+import os
+import subprocess
+import tempfile
+import shutil
+import yaml
+
+# Parse command-line arguments
+parser = argparse.ArgumentParser(
+    description="Build a Debian source package with a debdiff."
+)
+parser.add_argument(
+    '--config',
+    type=str,
+    required=True,
+    help='Path to the YAML configuration file'
+)
+parser.add_argument(
+    '--output-dir',
+    type=str,
+    help='Optional directory to preserve resulting files'
+)
+args = parser.parse_args()
+
+# Load configuration from YAML file
+with open(args.config, 'r') as f:
+    config = yaml.safe_load(f)
+
+# Create a temporary directory
+with tempfile.TemporaryDirectory() as temp_dir:
+    # Download the original Debian source package using dget
+    dsc_url = config['dsc_url']
+    subprocess.run(['dget', '-d', dsc_url], cwd=temp_dir, check=True)
+    print("✅ Original source package downloaded successfully.")
+
+    # Determine the .dsc file name
+    dsc_file = os.path.join(temp_dir, os.path.basename(dsc_url))
+
+    # Verify the SHA256 checksum of the .dsc file
+    with open(dsc_file, 'rb') as f:
+        file_data = f.read()
+        sha256sum = hashlib.sha256(file_data).hexdigest()
+
+    expected_sha256 = config['dsc_sha256sum']
+    if sha256sum != expected_sha256:
+        raise ValueError(
+            f"SHA256 checksum does not match!\n"
+            f"Expected: {expected_sha256}\n"
+            f"Actual:   {sha256sum}"
+        )
+    print("✅ Checksum of original source package matched.")
+
+    # Unpack the source package
+    subprocess.run(['dpkg-source', '-x', dsc_file], cwd=temp_dir, check=True)
+
+    # Find the unpacked directory
+    unpacked_dirs = [
+        d for d in os.listdir(temp_dir)
+        if os.path.isdir(os.path.join(temp_dir, d))
+    ]
+    if not unpacked_dirs:
+        raise RuntimeError("No unpacked source directory found.")
+    unpacked_dir = os.path.join(temp_dir, unpacked_dirs[0])
+
+    # Apply the debdiff
+    debdiff_path = config.get('debdiff_file')
+    if debdiff_path:
+        if not os.path.isabs(debdiff_path):
+            config_dir = os.path.dirname(args.config)
+            debdiff_path = os.path.abspath(os.path.join(config_dir,
+                                                        debdiff_path))
+        subprocess.run(
+            ['patch', '-p1', '-i', debdiff_path], cwd=unpacked_dir, check=True)
+        print("✅ Debdiff applied successfully.")
+    else:
+        print("⚠️  No debdiff provided.")
+
+    # Determine number of CPUs for parallel build
+    nproc_result = subprocess.run(
+                       ['nproc'], stdout=subprocess.PIPE, text=True,
+                       check=True)
+    num_cpus = nproc_result.stdout.strip()
+
+    # Build the resulting source package using sbuild
+    suite = config['suite']
+    subprocess.run(
+        ['sbuild', '--verbose', '-d', suite, '--no-clean-source',
+         '--dpkg-source-opt=--no-check', f'-j{num_cpus}'],
+        cwd=unpacked_dir,
+        check=True
+    )
+    print("✅ Source package built successfully.")
+
+    # Copy results if output-dir is specified
+    if args.output_dir:
+        os.makedirs(args.output_dir, exist_ok=True)
+
+        # Find the .changes file
+        changes_files = glob.glob(os.path.join(temp_dir, '*.changes'))
+        if not changes_files:
+            raise RuntimeError("No .changes file found to extract artifacts.")
+        changes_file = changes_files[0]
+
+        # Run dcmd to get the list of files
+        result = subprocess.run(
+            ['dcmd', changes_file],
+            cwd=temp_dir,
+            check=True,
+            stdout=subprocess.PIPE,
+            text=True
+        )
+
+        # Parse the output to get file paths
+        files_to_copy = [
+            line.split()[-1] for line in result.stdout.strip().splitlines()]
+
+        # Add any *.build files
+        build_files = glob.glob(os.path.join(temp_dir, '*.build'))
+        files_to_copy.extend(build_files)
+
+        # Copy files
+        for file_path in files_to_copy:
+            full_path = os.path.join(temp_dir, file_path)
+            if os.path.exists(full_path):
+                shutil.copy(full_path, args.output_dir)
+
+        print(f"📦 Results copied to: {args.output_dir}")