Avoid raw print.

changelogs/fragments/630-stderr.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - "Prefer stderr for error messages during building Ansible, and the logging facility for warnings in changelog related code (https://github.com/ansible-community/antsibull/pull/630)."

src/antsibull/build_ansible_commands.py

@@ -443,7 +443,8 @@ def prepare_command() -> int:
         print(
             f"{build_filename} is for version {build_ansible_version} but we need"
             f' {app_ctx.extra["ansible_version"].major}'
-            f'.{app_ctx.extra["ansible_version"].minor}'
+            f'.{app_ctx.extra["ansible_version"].minor}',
+            file=sys.stderr,
         )
         return 1
 
@@ -481,7 +482,8 @@ def prepare_command() -> int:
     except ValueError as exc:
         print(
             "Error while validating existing dependencies against"
-            f" build version ranges and constraints: {exc}"
+            f" build version ranges and constraints: {exc}",
+            file=sys.stderr,
         )
         return 1
 
@@ -649,9 +651,11 @@ def rebuild_single_command() -> int:
         if dep_errors:
             is_error = app_ctx.extra["ansible_version"] >= PypiVer("6.3.0")
             warning_error = "ERROR" if is_error else "WARNING"
-            print(f"{warning_error}: found collection dependency errors!")
+            print(
+                f"{warning_error}: found collection dependency errors!", file=sys.stderr
+            )
             for error in dep_errors:
-                print(f"{warning_error}: {error}")
+                print(f"{warning_error}: {error}", file=sys.stderr)
             if is_error:
                 return 3
 

src/antsibull/build_changelog.py

@@ -748,6 +748,7 @@ def _get_changelog_bytes(changelog: Changelog, text_format: TextFormat) -> bytes
     def _append_core_porting_guide_bytes(
         renderer: AbstractRenderer, changelog: Changelog
     ) -> None:
+        flog = mlog.fields(func="_append_core_porting_guide_bytes")
         core_porting_guide = changelog.core_collector.porting_guide
         if core_porting_guide:
             lines = core_porting_guide.decode("utf-8").splitlines()
@@ -766,7 +767,7 @@ def _append_core_porting_guide_bytes(
                     continue
                 append_lines.append(line)
             if not found_empty:
-                print("WARNING: cannot find TOC of ansible-core porting guide!")
+                flog.warning("Cannot find TOC of ansible-core porting guide!")
             if append_lines:
                 renderer.add_text(
                     "\n".join(append_lines), text_format=TextFormat.RESTRUCTURED_TEXT

src/antsibull/changelog.py

@@ -34,6 +34,7 @@
 from antsibull_core.ansible_core import get_ansible_core
 from antsibull_core.dependency_files import DependencyFileData, DepsFile
 from antsibull_core.galaxy import CollectionDownloader, GalaxyContext
+from antsibull_core.logging import log
 from antsibull_core.schemas.collection_meta import (
     CollectionsMetadata,
     RemovalInformation,
@@ -47,6 +48,8 @@
 from packaging.version import Version as PypiVer
 from semantic_version import Version as SemVer
 
+mlog = log.fields(mod=__name__)
+
 
 class ChangelogData:
     """
@@ -198,6 +201,7 @@ def __init__(self, collection: str, versions: t.ValuesView[str]):
     async def _get_changelog(
         self, version: SemVer, collection_downloader: CollectionDownloader
     ) -> ChangelogData | None:
+        flog = mlog.fields(func="_get_changelog")
         path = await collection_downloader.download(self.collection, version)
         changelog_bytes = read_changelog_file(path)
         if changelog_bytes is None:
@@ -208,8 +212,8 @@ async def _get_changelog(
                 self.collection, str(version), changelog_data
             )
         except Exception as exc:  # pylint: disable=broad-except
-            print(
-                f"WARNING: cannot load changelog of {self.collection} {version} due to {exc}"
+            flog.warning(
+                f"Cannot load changelog of {self.collection} {version} due to {exc}"
             )
             return None
 
@@ -727,6 +731,7 @@ def _populate_ansible_changelog(
     collection_metadata: CollectionsMetadata,
     ansible_version: PypiVer,
 ) -> None:
+    flog = mlog.fields(func="_populate_ansible_changelog")
     for collection, metadata in collection_metadata.collections.items():
         if metadata.removal:
             fragment_version = _get_removal_entry(
@@ -737,8 +742,8 @@ def _populate_ansible_changelog(
                 if version in ansible_changelog.changes.releases:
                     ansible_changelog.changes.add_fragment(fragment, version)
                 else:
-                    print(
-                        f"WARNING: found changelog entry for {version}, which does not yet exist"
+                    flog.warning(
+                        f"Found changelog entry for {version}, which does not yet exist"
                     )
 
     for collection, removed_metadata in collection_metadata.removed_collections.items():
@@ -750,8 +755,8 @@ def _populate_ansible_changelog(
             if version in ansible_changelog.changes.releases:
                 ansible_changelog.changes.add_fragment(fragment, version)
             else:
-                print(
-                    f"WARNING: found changelog entry for {version}, which does not yet exist"
+                flog.warning(
+                    f"Found changelog entry for {version}, which does not yet exist"
                 )
 
 
@@ -763,6 +768,7 @@ def get_changelog(
     ansible_changelog: ChangelogData | None = None,
     galaxy_context: GalaxyContext | None = None,
 ) -> Changelog:
+    flog = mlog.fields(func="get_changelog")
     dependencies: dict[str, DependencyFileData] = {}
 
     ansible_changelog = ansible_changelog or ChangelogData.ansible(directory=deps_dir)
@@ -781,7 +787,7 @@ def get_changelog(
             deps.deps.pop("_python", None)
             version = PypiVer(deps.ansible_version)
             if version > ansible_version:
-                print(
+                flog.info(
                     f"Ignoring {path}, since {deps.ansible_version}"
                     f" is newer than {ansible_version}"
                 )