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.

Warning

This JSON format is currently experimental and subject to change.

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=="
      }
    ]
  }
}