{
  "id": "python/pip-resolution-too-deep-backtracking",
  "signature": "ERROR: Cannot install package-a==1.0 and package-b==2.0 because these package versions have conflicting dependencies.\nThe conflict is caused by:\n    The user requested package-a==1.0\n    package-b 2.0 depends on package-a<1.0",
  "signature_zh": "错误：无法安装 package-a==1.0 和 package-b==2.0，因为这些包版本的依赖项存在冲突。\n冲突由以下原因引起：\n    用户请求 package-a==1.0\n    package-b 2.0 依赖于 package-a<1.0",
  "regex": "ERROR:\\ Cannot\\ install\\ package\\-a==1\\.0\\ and\\ package\\-b==2\\.0\\ because\\ these\\ package\\ versions\\ have\\ conflicting\\ dependencies\\.\\\nThe\\ conflict\\ is\\ caused\\ by:\\\n\\ \\ \\ \\ The\\ user\\ requested\\ package\\-a==1\\.0\\\n\\ \\ \\ \\ package\\-b\\ 2\\.0\\ depends\\ on\\ package\\-a<1\\.0",
  "domain": "python",
  "category": "install_error",
  "subcategory": null,
  "root_cause": "The dependency graph is unsatisfiable: two pinned requirements transitively require incompatible versions of a shared package.",
  "root_cause_type": "generic",
  "root_cause_zh": "依赖图无法满足：两个固定版本的需求传递性地要求共享包的互不兼容版本。",
  "versions": [
    {
      "version": "3.x",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Force install does not resolve version conflicts; pip still refuses to pick a solution.",
      "fail_rate": 0.85,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "The legacy resolver may install an inconsistent set, leading to runtime ImportErrors later.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Unpinned installs may still conflict on transitive constraints and reproduce the error.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "",
      "success_rate": 0.9,
      "how": "pip install 'package-a>=0.9,<1.0' 'package-b==2.0'",
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "success_rate": 0.85,
      "how": "pip install --dry-run --report report.json package-a==1.0 package-b==2.0\npython -m json.tool report.json | less",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.86,
  "fix_success_rate": 0.8,
  "resolvable": "partial",
  "first_seen": "2024-05-08",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}