add second search of packages version, if package is older than branch

build.py

@@ -92,6 +92,19 @@ def api_get_source_package_version(branch: str, package_name: str) -> str:
     response = requests.get(api_url, params)
     if response.status_code != 200:
         print(response)
+        api_url = "https://rdb.altlinux.org/api/site/package_versions"
+        params = {"arch": "x86_64", "package_type": "source", "name": package_name}
+        response = requests.get(api_url, params)
+        if response.status_code != 200:
+            print(response)
+            raise RuntimeError(
+                    f"failed to retrieve source package version: source package {package_name!r}, branch {branch!r} "
+            )
+        result = response.json()
+        for v in result["versions"]:
+            if v["branch"] == branch:
+                return v["version"]
+
         raise RuntimeError(
             f"failed to retrieve source package version: source package {package_name!r}, branch {branch!r} "
         )