Server error 500: Cannot read properties of undefined (reading 'mimetype')

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#1

Question/Issue:
I’m trying to use the ingestion feature of edge-impulse-runner-rs, but every time I upload the sample I get a 500 Internal Server Error with the message Cannot read properties of undefined (reading 'mimetype').

Project ID:
1105093

Context/Use case:
Uploading sensor data with edge-impulse-runner-rs ingestion.

Steps to Reproduce:

  1. Get an ingestion API key for your project
  2. Create an ingestion struct with the API key
  3. Call upload_sample.

Expected Results:
I expect response 200 (success).

Actual Results:
I got response 500 (internal server error).

Reproducibility:
Always

Environment:

  • Platform: NA
  • Build Environment Details: NA
  • OS Version: Linux (NixOS)
  • Edge Impulse Version (Firmware): NA
  • Edge Impulse CLI Version: NA
  • Project Version: NA
  • Custom Blocks / Impulse Configuration: NA
  • edge-impulse-runner-rs version: 2.0.0 (commit rev c4851b312deb2a2776743c8a6f73f12f38f8a34b)
    Logs/Attachments: 
=== Request Details ===
URL: https://ingestion.edgeimpulse.com/api/training/data
Device ID: None
Device Type: nRF52832
Sensors: [Sensor { name: "accelX", units: "m/s2" }, Sensor { name: "accelY", units: "m/s2" }, Sensor { name: "accelZ", units: "m/s2" }, Sensor { name: "gyroX", units: "rad" }, Sensor { name: "gyroY", units: "rad" }, Sensor { name: "gyroZ", units: "rad" }]
Data size: 6 sensors, 500 samples
=== Request Headers ===
{
    "x-api-key": "(hidden)",
    "x-file-name": "None.json",
    "x-label": "Motionless",
}
=== Response ===
Status: 500 Internal Server Error
Headers: {
    "date": "Fri, 04 Sep 2026 23:42:45 GMT",
    "content-type": "text/plain",
    "transfer-encoding": "chunked",
    "connection": "keep-alive",
    "access-control-allow-origin": "*",
    "content-security-policy": "default-src 'none'; frame-ancestors 'none'; form-action 'none';",
    "x-content-type-options": "nosniff",
    "x-frame-options": "DENY",
    "x-xss-protection": "1; mode=block",
    "referrer-policy": "strict-origin",
    "cache-control": "s-maxage=0,public,no-cache,no-store,must-revalidate",
    "strict-transport-security": "max-age=63072000",
}
Body: Cannot read properties of undefined (reading 'mimetype')