Checks if the parsed version constraint is empty (unsatisfiable). (#891)

Author: 0x00-pl

src/poetry/core/version/requirements.py

@@ -81,6 +81,11 @@ def __init__(self, requirement_string: str) -> None:
                 f'The requirement is invalid: invalid version constraint "{constraint}"'
             )
 
+        if self.constraint.is_empty():
+            raise InvalidRequirementError(
+                f'The requirement is invalid: unsatisfiable requirement: "{constraint}"'
+            )
+
         self.pretty_constraint = constraint
 
         marker = next(parsed.find_data("marker_spec"), None)

tests/version/test_requirements.py

@@ -131,6 +131,7 @@ def test_requirement(string: str, expected: dict[str, Any]) -> None:
     [
         ("foo!", "Unexpected character at column 4\n\nfoo!\n   ^\n"),
         ("foo (>=bar)", 'invalid version constraint ">=bar"'),
+        ("foo (>=0.2,<0.1)", 'unsatisfiable requirement: ">=0.2,<0.1"'),
         ("name @ file:/.", "invalid URL"),
     ],
 )