add --info flag

hydra/_internal/config_loader_impl.py

@@ -147,11 +147,11 @@ def load_configuration(
         parsed_overrides = [self._parse_override(override) for override in overrides]
 
         if config_name is not None and not self.repository.config_exists(config_name):
-            # TODO: handle schema as a special case
-            descs = [
-                f"\t{src.path} (from {src.provider})"
-                for src in self.repository.get_sources()
-            ]
+            descs = []
+            for src in self.repository.get_sources():
+                if src.provider != "schema":
+                    descs.append(f"\t{repr(src)}")
+
             lines = "\n".join(descs)
             raise MissingConfigException(
                 missing_cfg_file=config_name,

hydra/_internal/hydra.py

@@ -10,7 +10,7 @@
 
 from omegaconf import DictConfig, OmegaConf, open_dict
 
-from hydra._internal.utils import get_column_widths
+from hydra._internal.utils import get_column_widths, run_and_report
 from hydra.core.config_loader import ConfigLoader
 from hydra.core.config_search_path import ConfigSearchPath
 from hydra.core.hydra_config import HydraConfig
@@ -21,6 +21,7 @@
     configure_log,
     run_job,
     setup_globals,
+    simple_stdout_log_config,
 )
 from hydra.errors import MissingConfigException
 from hydra.plugins.completion_plugin import CompletionPlugin
@@ -85,16 +86,6 @@ def __init__(self, task_name: str, config_loader: ConfigLoader) -> None:
         """
         setup_globals()
         self.config_loader = config_loader
-
-        for source in config_loader.get_sources():
-            # if specified, make sure main config search path exists
-            if source.provider == "main":
-                if not source.exists(""):
-                    raise MissingConfigException(
-                        missing_cfg_file=source.path,
-                        message=f"Primary config dir not found: {source}",
-                    )
-
         JobRuntime().set("name", task_name)
 
     def run(
@@ -146,18 +137,35 @@ def get_sanitized_hydra_cfg(src_cfg: DictConfig) -> DictConfig:
             del cfg.hydra["help"]
         return cfg
 
-    def show_cfg(
-        self, config_name: Optional[str], overrides: List[str], cfg_type: str
-    ) -> None:
+    def _get_cfg(
+        self,
+        config_name: Optional[str],
+        overrides: List[str],
+        cfg_type: str,
+        with_log_configuration: bool,
+    ) -> DictConfig:
         assert cfg_type in ["job", "hydra", "all"]
         cfg = self.compose_config(
-            config_name=config_name, overrides=overrides, with_log_configuration=True
+            config_name=config_name,
+            overrides=overrides,
+            with_log_configuration=with_log_configuration,
         )
         if cfg_type == "job":
             with open_dict(cfg):
                 del cfg["hydra"]
         elif cfg_type == "hydra":
             cfg = self.get_sanitized_hydra_cfg(cfg)
+        return cfg
+
+    def show_cfg(
+        self, config_name: Optional[str], overrides: List[str], cfg_type: str
+    ) -> None:
+        cfg = self._get_cfg(
+            config_name=config_name,
+            overrides=overrides,
+            cfg_type=cfg_type,
+            with_log_configuration=False,
+        )
         print(cfg.pretty())
 
     @staticmethod
@@ -302,6 +310,11 @@ def _log_header(header: str, prefix: str = "", filler: str = "-") -> None:
         log.debug(prefix + header)
         log.debug(prefix + "".ljust(len(header), filler))
 
+    @staticmethod
+    def _log_footer(header: str, prefix: str = "", filler: str = "-") -> None:
+        assert log is not None
+        log.debug(prefix + "".ljust(len(header), filler))
+
     def _print_plugins(self) -> None:
         assert log is not None
         self._log_header(header="Installed Hydra Plugins", filler="*")
@@ -337,11 +350,11 @@ def _print_search_path(self) -> None:
             box.append([sp.provider, sp.full_path()])
 
         provider_pad, search_path_pad = get_column_widths(box)
+        header = "| {} | {} |".format(
+            "Provider".ljust(provider_pad), "Search path".ljust(search_path_pad)
+        )
         self._log_header(
-            "| {} | {} |".format(
-                "Provider".ljust(provider_pad), "Search path".ljust(search_path_pad)
-            ),
-            filler="-",
+            header=header, filler="-",
         )
 
         for source in self.config_loader.get_sources():
@@ -351,6 +364,7 @@ def _print_search_path(self) -> None:
                     source.full_path().ljust(search_path_pad),
                 )
             )
+        self._log_footer(header=header, filler="-")
 
     def _print_composition_trace(self) -> None:
         # Print configurations used to compose the config object
@@ -372,15 +386,13 @@ def _print_composition_trace(self) -> None:
         padding = get_column_widths(box)
         del box[0]
 
-        self._log_header(
-            "| {} | {} | {} | {} |".format(
-                "Config name".ljust(padding[0]),
-                "Search path".ljust(padding[1]),
-                "Provider".ljust(padding[2]),
-                "Schema provider".ljust(padding[3]),
-            ),
-            filler="-",
+        header = "| {} | {} | {} | {} |".format(
+            "Config name".ljust(padding[0]),
+            "Search path".ljust(padding[1]),
+            "Provider".ljust(padding[2]),
+            "Schema provider".ljust(padding[3]),
         )
+        self._log_header(header=header, filler="-")
 
         for row in box:
             log.debug(
@@ -392,6 +404,8 @@ def _print_composition_trace(self) -> None:
                 )
             )
 
+        self._log_footer(header=header, filler="-")
+
     def _print_plugins_profiling_info(self, top_n: int) -> None:
         assert log is not None
         stats = Plugins.instance().get_stats()
@@ -417,9 +431,9 @@ def _print_plugins_profiling_info(self, top_n: int) -> None:
             filler="-",
         )
 
+        header = f"| {box[0][0].ljust(padding[0])} | {box[0][1].ljust(padding[1])} |"
         self._log_header(
-            f"| {box[0][0].ljust(padding[0])} | {box[0][1].ljust(padding[1])} |",
-            filler="-",
+            header=header, filler="-",
         )
         del box[0]
 
@@ -428,6 +442,8 @@ def _print_plugins_profiling_info(self, top_n: int) -> None:
             b = row[1].ljust(padding[1])
             log.debug(f"| {a} | {b} |")
 
+        self._log_footer(header=header, filler="-")
+
     def _print_debug_info(self) -> None:
         assert log is not None
         if log.isEnabledFor(logging.DEBUG):
@@ -452,6 +468,16 @@ def compose_config(
                        otherwise forces specific behavior.
         :return:
         """
+
+        for source in self.config_loader.get_sources():
+            # if specified, make sure main config search path exists
+            if source.provider == "main":
+                if not source.exists(""):
+                    raise MissingConfigException(
+                        missing_cfg_file=source.path,
+                        message=f"Primary config dir not found: {source}",
+                    )
+
         cfg = self.config_loader.load_configuration(
             config_name=config_name, overrides=overrides, strict=strict
         )
@@ -466,3 +492,28 @@ def compose_config(
             log = logging.getLogger(__name__)
             self._print_debug_info()
         return cfg
+
+    def show_info(self, config_name: Optional[str], overrides: List[str]) -> None:
+        from .. import __version__
+
+        simple_stdout_log_config(level=logging.DEBUG)
+        global log
+        log = logging.getLogger(__name__)
+        self._log_header(f"Hydra {__version__}", filler="=")
+        self._print_plugins()
+        self._print_search_path()
+        self._print_plugins_profiling_info(top_n=10)
+
+        cfg = run_and_report(
+            lambda: self._get_cfg(
+                config_name=config_name,
+                overrides=overrides,
+                cfg_type="job",
+                with_log_configuration=False,
+            )
+        )
+        self._print_composition_trace()
+
+        log.debug("\n")
+        self._log_header(header="Config", filler="*")
+        log.debug(cfg.pretty())

hydra/_internal/utils.py

@@ -183,9 +183,9 @@ def create_config_search_path(search_path_dir: Optional[str]) -> ConfigSearchPat
     return search_path
 
 
-def run_and_report(func: Any) -> None:
+def run_and_report(func: Any) -> Any:
     try:
-        func()
+        return func()
     except (HydraException, OmegaConfBaseException) as ex:
         if "HYDRA_FULL_ERROR" in os.environ and os.environ["HYDRA_FULL_ERROR"] == "1":
             print_exc()
@@ -231,9 +231,12 @@ def run_hydra(
         calling_file, calling_module, config_dir
     )
 
-    hydra = Hydra.create_main_hydra2(
-        task_name=task_name, config_search_path=search_path, strict=strict
+    hydra = run_and_report(
+        lambda: Hydra.create_main_hydra2(
+            task_name=task_name, config_search_path=search_path, strict=strict
+        )
     )
+
     try:
         if args.help:
             hydra.app_help(config_name=config_name, args_parser=args_parser, args=args)
@@ -245,10 +248,12 @@ def run_hydra(
             sys.exit(0)
 
         has_show_cfg = args.cfg is not None
-        num_commands = args.run + has_show_cfg + args.multirun + args.shell_completion
+        num_commands = (
+            args.run + has_show_cfg + args.multirun + args.shell_completion + args.info
+        )
         if num_commands > 1:
             raise ValueError(
-                "Only one of --run, --multirun,  -cfg and --shell_completion can be specified"
+                "Only one of --run, --multirun,  -cfg, --info and --shell_completion can be specified"
             )
         if num_commands == 0:
             args.run = True
@@ -280,6 +285,8 @@ def run_hydra(
                     config_name=config_name, overrides=args.overrides
                 )
             )
+        elif args.info:
+            hydra.show_info(config_name=config_name, overrides=args.overrides)
         else:
             sys.stderr.write("Command not specified\n")
             sys.exit(1)
@@ -363,6 +370,10 @@ def get_args_parser() -> argparse.ArgumentParser:
         "-cn",
         help="Overrides the config_name specified in hydra.main()",
     )
+
+    parser.add_argument(
+        "--info", "-i", action="store_true", help="Print Hydra information",
+    )
     return parser
 
 

hydra/core/utils.py

@@ -21,6 +21,15 @@
 log = logging.getLogger(__name__)
 
 
+def simple_stdout_log_config(level: int = logging.INFO) -> None:
+    root = logging.getLogger()
+    root.setLevel(level)
+    handler = logging.StreamHandler(sys.stdout)
+    formatter = logging.Formatter("%(message)s")
+    handler.setFormatter(formatter)
+    root.addHandler(handler)
+
+
 def configure_log(
     log_config: DictConfig, verbose_config: Union[bool, str, Sequence[str]]
 ) -> None:

news/662.feature

@@ -0,0 +1 @@
+Add a new --info flag to show Hydra debug information without running the user function.

tests/test_compose.py

@@ -224,7 +224,9 @@ def test_compose(
             assert ret == expected
 
 
-def test_missing_init_py_error(hydra_global_context: TGlobalHydraContext) -> None:
+def test_missing_init_py_error(
+    restore_singletons: Any, hydra_global_context: TGlobalHydraContext
+) -> None:
     with pytest.raises(
         Exception,
         match=re.escape(
@@ -235,7 +237,9 @@ def test_missing_init_py_error(hydra_global_context: TGlobalHydraContext) -> Non
         with hydra_global_context(
             config_dir="../hydra/test_utils/configs/missing_init_py"
         ):
-            ...
+            hydra = GlobalHydra.instance().hydra
+            assert hydra is not None
+            hydra.compose_config(config_name=None, overrides=[])
 
 
 def test_initialize_with_file(restore_singletons: Any) -> None:

tests/test_core_utils.py

@@ -9,7 +9,7 @@
 from hydra.core.hydra_config import HydraConfig
 
 
-def test_foo(restore_singletons: Any) -> Any:
+def test_accessing_hydra_config(restore_singletons: Any) -> Any:
     utils.setup_globals()
 
     config_loader = ConfigLoaderImpl(

tests/test_hydra.py

@@ -553,6 +553,7 @@ def test_sweep_complex_defaults(
 --config_path,-cp : Overrides the config_path specified in hydra.main().
                     The config_path is relative to the Python file declaring @hydra.main()
 --config_name,-cn : Overrides the config_name specified in hydra.main()
+--info,-i : Print Hydra information
 Overrides : Any key=value arguments to override config values (use dots for.nested=overrides)
 """,
             id="overriding_help_template:$FLAGS_HELP",
@@ -600,6 +601,7 @@ def test_sweep_complex_defaults(
 --config_path,-cp : Overrides the config_path specified in hydra.main().
                     The config_path is relative to the Python file declaring @hydra.main()
 --config_name,-cn : Overrides the config_name specified in hydra.main()
+--info,-i : Print Hydra information
 Overrides : Any key=value arguments to override config values (use dots for.nested=overrides)
 """,
             id="overriding_hydra_help_template:$FLAGS_HELP",