Merge pull request #103 from nix-community/logging

cleaner eval error messages

.github/PULL_REQUEST_TEMPLATE.md

@@ -4,7 +4,7 @@ The following points apply when adding a new repository to repos.json
 - [ ] By including this repository in NUR I give permission to license the
 content under the MIT license.
 
-Clarifiction where license should apply: 
+Clarification where license should apply:
 The license above does not apply to the packages built by the
 Nix Packages collection, merely to the package descriptions (i.e., Nix
 expressions, build scripts, etc.).  It also might not apply to patches

nur/__init__.py

@@ -1,19 +1,29 @@
 import argparse
+import logging
 import sys
 from typing import List
 
+from .combine import combine_command
 from .format_manifest import format_manifest_command
 from .index import index_command
-from .update import update_command
 from .path import ROOT
+from .update import update_command
 
-from .combine import combine_command
+LOG_LEVELS = dict(
+    debug=logging.DEBUG,
+    info=logging.INFO,
+    error=logging.ERROR,
+    critical=logging.CRITICAL,
+)
 
 
 def parse_arguments(argv: List[str]) -> argparse.Namespace:
     parser = argparse.ArgumentParser(
         prog=argv[0], description="nur management commands"
     )
+    parser.add_argument(
+        "--log-level", type=str, default="debug", choices=list(LOG_LEVELS.keys())
+    )
 
     subparsers = parser.add_subparsers(description="subcommands")
 
@@ -48,4 +58,6 @@ def parse_arguments(argv: List[str]) -> argparse.Namespace:
 
 def main() -> None:
     args = parse_arguments(sys.argv)
+    logging.basicConfig(level=LOG_LEVELS[args.log_level])
+
     args.func(args)

nur/error.py

@@ -1,2 +1,6 @@
 class NurError(Exception):
     pass
+
+
+class EvalError(NurError):
+    pass

nur/update.py

@@ -5,7 +5,7 @@ import tempfile
 from argparse import Namespace
 from pathlib import Path
 
-from .error import NurError
+from .error import EvalError
 from .manifest import Repo, load_manifest, update_lock_file
 from .path import EVALREPO_PATH, LOCK_PATH, MANIFEST_PATH, nixpkgs_path
 from .prefetch import prefetch
@@ -55,9 +55,9 @@ import {EVALREPO_PATH} {{
         try:
             res = proc.wait(5)
         except subprocess.TimeoutExpired:
-            raise NurError(f"evaluation for {repo.name} timed out of after 5 seconds")
+            raise EvalError(f"evaluation for {repo.name} timed out of after 5 seconds")
         if res != 0:
-            raise NurError(f"{repo.name} does not evaluate:\n$ {' '.join(cmd)}")
+            raise EvalError(f"{repo.name} does not evaluate:\n$ {' '.join(cmd)}")
 
 
 def update(repo: Repo) -> Repo:
@@ -71,15 +71,21 @@ def update(repo: Repo) -> Repo:
 
 
 def update_command(args: Namespace) -> None:
+    logging.basicConfig(level=logging.INFO)
+
     manifest = load_manifest(MANIFEST_PATH, LOCK_PATH)
 
     for repo in manifest.repos:
         try:
             update(repo)
-        except Exception:
+        except EvalError as e:
             if repo.locked_version is None:
                 # likely a repository added in a pull request, make it fatal then
                 raise
+            # Do not print stack traces
+            logger.error(f"repository {repo.name} failed to evaluate: {e}")
+        except Exception:
+            # for non-evaluation errors we want the stack trace
             logger.exception(f"Failed to updated repository {repo.name}")
 
     update_lock_file(manifest.repos, LOCK_PATH)