Build Trace Entry

• 1. Property key
  • 1.1. Property drvPath
  • 1.2. Property outputName
• 2. Property value
  • 2.1. Property outPath
  • 2.2. Property signatures
    • 2.2.1. Signature
      • 2.2.1.1. Property keyName
      • 2.2.1.2. Property sig

Title: Build Trace Entry

Description: A record of a successful build outcome for a specific derivation output.

This schema describes the JSON representation of an entry in a build trace.

Warning

This JSON format is currently experimental and subject to change.

Version History

• Version 1: Original format

• Version 2:

  • Remove dependentRealisations

• Version 3:

  • Use drvPath not drvHash to refer to derivation in a more conventional way.
  • Separate into key and value
  • Use 2nd version of signatures format (objects, not strings)

1. Property key

Title: Build Trace Key

Description: A build trace entry is a key-value pair. This is the “key” part, referring to a derivation and output.

1.1. Property drvPath

Title: Derivation Path

Description: The store path of the derivation that was built.

1.2. Property outputName

Title: Output Name

Description: Name of the specific output (e.g., “out”, “dev”, “doc”)

2. Property value

Title: Build Trace Value

Description: A build trace entry is a key-value pair. This is the “value” part, describing an output.

2.1. Property outPath

Title: Output Store Path

Description: The path to the store object that resulted from building this derivation for the given output name.

2.2. Property signatures

Title: Build Signatures

Description: A set of cryptographic signatures attesting to the authenticity of this build trace entry.

2.2.1. Signature

Title: Signature

Description: A cryptographic signature along with the name of the key that produced it.

This schema describes the JSON representation of signatures as used in various Nix JSON APIs.

Version History

• Version 1: Colon-separated string in the format <key-name>:<signature-in-Base64>

• Version 2: Structured object with keyName and sig fields

2.2.1.1. Property keyName

Title: Key Name

Description: The name of the key used to produce this signature

2.2.1.2. Property sig

Title: Signature Data

Description: The raw signature bytes, Base64-encoded

Examples

Simple build trace entry

{
  "key": {
    "drvPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar.drv",
    "outputName": "foo"
  },
  "value": {
    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo",
    "signatures": []
  }
}

Build trace entry with signature

{
  "key": {
    "drvPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-bar.drv",
    "outputName": "foo"
  },
  "value": {
    "outPath": "g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo.drv",
    "signatures": [
      {
        "keyName": "asdf",
        "sig": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=="
      }
    ]
  }
}