helpers: logging: reduce the risk of a cyclical import

Lazy load pmb.config.styles and move the pmb.__version__ print elsewhere
so the logging module is (closer to) a standalone entity. This is
necessary to be able to import it in pmb/helpers/apk.py otherwise we get
a cyclical dependency.

Signed-off-by: Caleb Connolly <caleb@postmarketos.org>

pmb/helpers/args.py

 # Copyright 2023 Oliver Smith
 # SPDX-License-Identifier: GPL-3.0-or-later
+import sys
+
 import pmb.config
 from pmb.core.context import Context
 from pmb.core.pkgrepo import pkgrepo_default_path
@@ -89,6 +91,7 @@ def init(args: PmbArgs) -> PmbArgs:
 
     # Initialize logs (we could raise errors below)
     pmb.helpers.logging.init(context.log, args.verbose, context.details_to_stdout)
+    pmb.helpers.logging.debug(f"Pmbootstrap v{pmb.__version__} (Python {sys.version})")
 
     # Initialization code which may raise errors
     if args.action not in [

pmb/helpers/logging.py

@@ -5,7 +5,6 @@ import os
 from pathlib import Path
 import sys
 from typing import Final, TextIO
-import pmb.config
 from pmb.meta import Cache
 
 logfd: TextIO
@@ -29,6 +28,12 @@ class log_handler(logging.StreamHandler):
         self.details_to_stdout = details_to_stdout
         self.quiet = False
 
+        # FIXME: importing pmb.config pulls in a whole lot of stuff
+        # and can easily lead to circular imports, so we defer it until here.
+        import pmb.config
+
+        self.styles = pmb.config.styles
+
     def emit(self, record):
         try:
             msg = self.format(record)
@@ -37,7 +42,7 @@ class log_handler(logging.StreamHandler):
             if self.details_to_stdout or (not self.quiet and record.levelno >= logging.INFO):
                 stream = self.stream
 
-                styles = pmb.config.styles
+                styles = self.styles
 
                 msg_col = (
                     msg.replace(
@@ -147,7 +152,6 @@ def init(logfile: Path, verbose: bool, details_to_stdout: bool = False):
     handler.setFormatter(formatter)
     root_logger.addHandler(handler)
 
-    logging.debug(f"Pmbootstrap v{pmb.__version__} (Python {sys.version})")
     if "--password" in sys.argv:
         sys.argv[sys.argv.index("--password") + 1] = "[REDACTED]"
     logging.debug(f"$ pmbootstrap {' '.join(sys.argv)}")