Draft pip unhandled exception handling

python/lib/dependabot/python/update_checker/poetry_version_resolver.rb

@@ -364,11 +364,18 @@ class PoetryErrorHandler < UpdateChecker
 
       # server response error codes while accessing package index
       SERVER_ERROR_CODES = T.let({
+        server500: /500 Server Error/,
         server502: /502 Server Error/,
         server503: /503 Server Error/,
         server504: /504 Server Error/
       }.freeze, T::Hash[T.nilable(String), Regexp])
 
+      # invalid configuration in pyproject.toml
+      POETRY_VIRTUAL_ENV_CONFIG = %r{pypoetry/virtualenvs(.|\n)*list index out of range}
+
+      # error related to local project as dependency in pyproject.toml
+      ERR_LOCAL_PROJECT_PATH = /Path (?<path>.*) for (?<dep>.*) does not exist/
+
       sig do
         params(
           dependencies: Dependabot::Dependency,
@@ -403,6 +410,7 @@ def sanitize_url(url)
       # rubocop:disable Metrics/PerceivedComplexity
       sig { params(error: Exception).void }
       def handle_poetry_error(error)
+        debugger
         Dependabot.logger.warn(error.message)
 
         if (msg = error.message.match(PoetryVersionResolver::INCOMPATIBLE_CONSTRAINTS) ||
@@ -418,6 +426,12 @@ def handle_poetry_error(error)
 
         raise DependencyFileNotResolvable, error.message if error.message.match(PYTHON_RANGE_NOT_SATISFIED)
 
+        if error.message.match(POETRY_VIRTUAL_ENV_CONFIG) || error.message.match(ERR_LOCAL_PROJECT_PATH)
+          msg = "Error while resolving pyproject.toml file"
+
+          raise DependencyFileNotResolvable, msg
+        end
+
         SERVER_ERROR_CODES.each do |(_error_codes, error_regex)|
           next unless error.message.match?(error_regex)
 

python/spec/dependabot/python/update_checker/poetry_version_resolver_spec.rb

@@ -486,6 +486,22 @@
       end
     end
 
+    context "with private registry authentication 504 Server Error" do
+      let(:response) do
+        "Creating virtualenv pylossmap-m4-85W1Y-py3.13 in /home/dependabot/.cache/pypoetry/virtualenvs
+        Updating dependencies
+        Resolving dependencies...
+
+        500 Server Error: Internal Server Error for url: http://acc-py-repo.cern.ch:8081/repository/vr-py-releases/simple/jinja2/"
+      end
+      it "raises a helpful error" do
+        expect { poetry_error_handler }.to raise_error(Dependabot::InconsistentRegistryResponse) do |error|
+          expect(error.message)
+            .to include("http://acc-py-repo.cern.ch")
+        end
+      end
+    end
+
     context "with private registry authentication 504 Server Error" do
       let(:response) do
         "Creating virtualenv alk-service-import-product-TbrdR40A-py3.8 in /home/dependabot/.cache/pypoetry/virtualenvs
@@ -550,5 +566,32 @@
         end
       end
     end
+
+    context "with a misconfigured pyproject.toml file" do
+      let(:response) do
+        "Creating virtualenv analysis-nlUUV3qa-py3.13 in pypoetry/virtualenvs
+        Updating dependencies
+        Resolving dependencies...
+        list index out of range"
+      end
+
+      it "raises a helpful error" do
+        expect { poetry_error_handler }.to raise_error(Dependabot::DependencyFileNotResolvable)
+      end
+    end
+
+    context "with a project is listed a dependency" do
+      let(:response) do
+        "Creating virtualenv kiota-serialization-multipart-GzD6BRdm-py3.13 in " \
+          "/home/dependabot/.cache/pypoetry/virtualenvs" \
+          "Updating dependencies" \
+          "Resolving dependencies..." \
+          "Path tmp/20250109-1637-dc4aky/json for kiota-serialization-json does not exist"
+      end
+
+      it "raises a helpful error" do
+        expect { poetry_error_handler }.to raise_error(Dependabot::DependencyFileNotResolvable)
+      end
+    end
   end
 end