Swift Package.resolved contains incorrect version when using 'from:'

[swiftty]

How are you running Renovate?

A Mend.io-hosted app

Which platform you running Renovate on?

GitHub.com

Which version of Renovate are you using?

"renovateVersion": "43.91.5"

Please tell us more about your question or problem

Since #41782, When using from: argument in Package.swift, the updated Package.resolved ends up containing an incorrect version that includes the from: constraint.

dependencies: [
    .package(url: "https://github.com/swiftlang/swift-syntax.git", from: "601.0.1"),
    ...
],

https://github.com/swiftty/api-diff-viewer/pull/6/changes

Logs (if relevant)

Logs

renovate deps log

{
  "currentValue": "from: \"601.0.1\"",
  "currentVersion": "601.0.1",
  "currentVersionAgeInDays": 358,
  "currentVersionTimestamp": "2025-04-02T20:32:36.000Z",
  "datasource": "github-tags",
  "depName": "swiftlang/swift-syntax",
  "isSingleVersion": false,
  "mostRecentTimestamp": "2026-03-20T19:02:25.000Z",
  "packageName": "swiftlang/swift-syntax",
  "registryUrl": "https://github.com",
  "sourceUrl": "https://github.com/swiftlang/swift-syntax",
  "versioning": "swift",
  "warnings": [],
  "updates": [
    {
      "bucket": "major",
      "newVersion": "603.0.0",
      "newValue": "from: \"603.0.0\"",
      "releaseTimestamp": "2026-03-06T16:56:48.000Z",
      "newVersionAgeInDays": 20,
      "newMajor": 603,
      "newMinor": 0,
      "newPatch": 0,
      "updateType": "major",
      "isBreaking": true,
      "isRange": true,
      "libYears": 0.9256168188736682,
      "branchName": "renovate/swiftlang-swift-syntax-603.x"
    }
  ]
}

swift build error log

error: /Users/runner/work/api-diff-viewer/api-diff-viewer/api-diff-viewer/Package.resolved file is corrupted or malformed; fix or delete the file to continue: dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: "The given data was not valid JSON.", underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840 "Unexpected character '6' in object around line 10, column 29." UserInfo={NSJSONSerializationErrorIndex=358, NSDebugDescription=Unexpected character '6' in object around line 10, column 29.})))

[jamietanna]

Ooh thanks for reporting 🙇

[jamietanna]

Converted into bug: #42188