Add exception handling

Author: evandowning

README.md

@@ -76,6 +76,12 @@ it-depends "ubuntu:libc6@2.31"
 it-depends "npm:lodash@>=4.17.0"
 ```
 
+To list resolvers compatible for the specified target, use the `--list` option:
+
+```shell
+it-depends . --list
+```
+
 It-Depends will output the full dependency hierarchy in JSON format. Additional output formats such
 as Graphviz/Dot are available via the `--output-format` option.
 
@@ -124,7 +130,7 @@ This is the resulting dependency graph:
 git clone https://github.com/trailofbits/it-depends
 cd it-depends
 make dev
-source .venv/bin/activate
+uv run it-depends --help
 ```
 
 Format and lint code before contributing

src/it_depends/_cli.py

@@ -37,7 +37,7 @@ def parse_path_or_package_name(
     return dependency
 
 
-def main() -> None:  # noqa: C901, PLR0912, PLR0915
+def main() -> None:  # noqa: C901, PLR0912, PLR0915, PLR0911
     settings = Settings()  # type: ignore[call-arg]
     setup_logger(settings.log_level)
 
@@ -61,6 +61,11 @@ def main() -> None:  # noqa: C901, PLR0912, PLR0915
         logger.exception(msg)
         return
 
+    # If this is a source repository, make sure the folder exists
+    if isinstance(repo, SourceRepository) and not repo.path.exists():
+        logger.error("The specified path does not exist: %s", repo.path)
+        return
+
     # Clear the database cache
     if settings.clear_cache:
         db_path = Path(settings.database)

src/it_depends/pip.py

@@ -285,6 +285,9 @@ def resolve(self, dependency: Dependency) -> Iterator[Package]:
                     recurse=False,
                 )
             )
+        except subprocess.CalledProcessError:
+            log.exception("Error using JohnnyDep to resolve %s", dependency.package)
+            return iter(())
         except ValueError as e:
             log.warning(str(e))
             return iter(())

src/it_depends/resolution.py

@@ -164,6 +164,7 @@ def resolve(  # noqa: C901, PLR0912, PLR0915
                 # Resolve from source repository
                 found_source_package = False
                 for resolver in resolvers():
+                    logger.debug("Trying to resolve %s using resolver %s", repo_or_spec, resolver.name)
                     if resolver.can_resolve_from_source(repo_or_spec):
                         source_package = resolver.resolve_from_source(repo_or_spec, cache=cache)
                         if source_package is None: