Merge pull request #4332 from python-poetry/reinstate-solution-providers

Bring back error solutions

poetry/console/application.py

@@ -26,6 +26,12 @@
 from .commands.command import Command
 
 
+if TYPE_CHECKING:
+    from crashtest.solution_providers.solution_provider_repository import (
+        SolutionProviderRepository,
+    )
+
+
 def load_command(name: str) -> Callable:
     def _load() -> Type[Command]:
         module = import_module(
@@ -159,6 +165,13 @@ def create_io(
 
         return io
 
+    def render_error(self, error: Exception, io: IO) -> None:
+        # We set the solution provider repository here to load providers
+        # only when an error occurs
+        self.set_solution_provider_repository(self._get_solution_provider_repository())
+
+        super().render_error(error, io)
+
     def _run(self, io: IO) -> int:
         self._disable_plugins = io.input.parameter_option("--no-plugins")
 
@@ -330,6 +343,20 @@ def _default_definition(self) -> "Definition":
 
         return definition
 
+    def _get_solution_provider_repository(self) -> "SolutionProviderRepository":
+        from crashtest.solution_providers.solution_provider_repository import (
+            SolutionProviderRepository,
+        )
+
+        from poetry.mixology.solutions.providers.python_requirement_solution_provider import (
+            PythonRequirementSolutionProvider,
+        )
+
+        repository = SolutionProviderRepository()
+        repository.register_solution_providers([PythonRequirementSolutionProvider])
+
+        return repository
+
 
 def main() -> int:
     return Application().run()

pyproject.toml

@@ -32,7 +32,7 @@ generate-setup-file = false
 python = "^3.6"
 
 poetry-core = { git = "https://github.com/python-poetry/poetry-core.git", branch = "master" }
-cleo = "^1.0.0a1"
+cleo = "^1.0.0a4"
 crashtest = "^0.3.0"
 requests = "^2.18"
 cachy = "^0.3.0"