Move back to print for logging to console in multiplatform builder

The log writer cannot be pickled to be used in multiprocess builds,
and therefore is broken most of the time. Using print prevents that.

buildrunner/__init__.py

@@ -583,7 +583,6 @@ def run(self):  # pylint: disable=too-many-statements,too-many-branches,too-many
         exit_explanation = None
         try:  # pylint: disable=too-many-nested-blocks
             with MultiplatformImageBuilder(
-                log=self.log,
                 docker_registry=self.global_config.get_docker_registry(),
                 keep_images=not self.cleanup_images,
                 temp_dir=self.global_config.get_temp_dir(),

buildrunner/docker/multiplatform_image_builder.py

@@ -10,7 +10,6 @@
 from multiprocessing import Manager, Process
 from platform import machine, system
 import shutil
-import sys
 import tempfile
 import uuid
 from typing import Dict, List, Optional
@@ -122,15 +121,13 @@ class MultiplatformImageBuilder:  # pylint: disable=too-many-instance-attributes
     # pylint: disable=too-many-arguments
     def __init__(
             self,
-            log=sys.stdout,
             docker_registry: Optional[str] = None,
             use_local_registry: bool = True,
             keep_images: bool = False,
             temp_dir: str = os.getcwd(),
             disable_multi_platform: bool = False,
             platform_builders: Optional[Dict[str, str]] = None,
     ):
-        self._log = log
         self._docker_registry = docker_registry
         self._mp_registry_info = None
         self._use_local_registry = use_local_registry
@@ -319,7 +316,7 @@ def _build_single_image(
         tagged_names = [f"{name}:{tag}" for tag in tags]
         builder = self._platform_builders.get(platform) if self._platform_builders else None
         logger.debug(f"Building tagged images {tagged_names}")
-        self._log.write(f"Building image for platform {platform} with {builder or 'default'} builder\n")
+        print(f"Building image for platform {platform} with {builder or 'default'} builder")
 
         if inject and isinstance(inject, dict):
             self._build_with_inject(
@@ -455,26 +452,26 @@ def get_path(file):
 
         if self._disable_multi_platform:
             platforms = [self.get_single_platform_to_build(platforms)]
-            self._log.write(
+            print(
                 f"{line}\n"
                 f"Note: Disabling multi-platform build, "
                 "this will only build a single-platform image.\n"
                 f"image: {sanitized_name} platform:{platforms[0]}\n"
-                f"{line}\n"
+                f"{line}"
             )
         else:
-            self._log.write(
+            print(
                 f"{line}\n"
                 f"Note: Building multi-platform images can take a long time, please be patient.\n"
                 "If you are running this locally, you can speed this up by using the "
                 "'--disable-multi-platform' CLI flag "
                 "or set the 'disable-multi-platform' flag in the global config file.\n"
-                f"{line}\n"
+                f"{line}"
             )
 
         processes = []
-        self._log.write(
-            f'Starting builds for {len(platforms)} platforms in {"parallel" if do_multiprocessing else "sequence"}\n'
+        print(
+            f'Starting builds for {len(platforms)} platforms in {"parallel" if do_multiprocessing else "sequence"}'
         )
         for platform in platforms:
             platform_image_name = f"{base_image_name}-{platform.replace('/', '-')}"

tests/test_multiplatform.py

@@ -75,7 +75,7 @@ def test_start_local_registry_on_build():
     registry_name = None
     volume_name = None
 
-    with MultiplatformImageBuilder(log=MagicMock()) as mp:
+    with MultiplatformImageBuilder() as mp:
         # Check that the registry is NOT running
         assert mp._mp_registry_info is None
         assert mp._local_registry_is_running is False