Uploading conan package to gitlab registry results in an internal server 500 error

Summary

In version 13.2 conan package upload was working normaly, with 13.3 the upload is now failing with 500 error.

Steps to reproduce

Have a working Conan package upload CI?CD pipeline
Upgrade to 13.3 and run pipeline

Example Project

A Premium (large) Customer reported issue in ZD internal only

What is the current bug behavior?

POST api call fail with 500 error.

What is the expected correct behavior?

POST api call succeeds.

Relevant logs and/or screenshots

{
  "time": "2020-09-07T11:10:46.635Z",
  "severity": "INFO",
  "duration_s": 0.03451,
  "db_duration_s": 0.00782,
  "view_duration_s": 0.02669,
  "status": 500,
  "method": "POST",
  "path": "/api/v4/packages/conan/v1/conans/ConanPckg/3.0/example-group+conan/beta/upload_urls",
  "params": [
    {
      "key": "conanfile.py",
      "value": null
    },
    {
      "key": "conanmanifest.txt",
      "value": null
    }
  ],
  "host": "gitlab.example.com",
  "remote_ip": "10.1.2.3, 10.1.2.4, 127.0.0.1",
  "ua": "Conan/1.29.0 (Python 3.8.1) python-requests/2.24.0",
  "route": "/api/:version/packages/conan/v1/conans/:package_name/:package_version/:package_username/:package_channel/upload_urls",
  "user_id": 2982,
  "username": "auser",
  "exception.class": "NoMethodError",
  "exception.message": "undefined method `string' for #<Unicorn::TeeInput:0x00007f2ee811fad0>",
  "exception.backtrace": [
    "lib/api/helpers/packages/conan/api_helpers.rb:142:in `file_names'",
    "lib/api/helpers/packages/conan/api_helpers.rb:33:in `recipe_upload_urls'",
    "lib/api/conan_packages.rb:231:in `block (3 levels) in <class:ConanPackages>'",
    "ee/lib/gitlab/middleware/ip_restrictor.rb:14:in `block in call'",
    "ee/lib/gitlab/ip_address_state.rb:10:in `with'",
    "ee/lib/gitlab/middleware/ip_restrictor.rb:13:in `call'",
    "lib/gitlab/metrics/elasticsearch_rack_middleware.rb:16:in `call'",
    "lib/gitlab/middleware/rails_queue_duration.rb:33:in `call'",
    "lib/gitlab/metrics/rack_middleware.rb:16:in `block in call'",
    "lib/gitlab/metrics/transaction.rb:61:in `run'",
    "lib/gitlab/metrics/rack_middleware.rb:16:in `call'",
    "lib/gitlab/request_profiler/middleware.rb:17:in `call'",
    "ee/lib/gitlab/jira/middleware.rb:19:in `call'",
    "lib/gitlab/middleware/go.rb:20:in `call'",
    "lib/gitlab/etag_caching/middleware.rb:13:in `call'",
    "lib/gitlab/middleware/multipart.rb:140:in `call'",
    "lib/gitlab/middleware/read_only/controller.rb:51:in `call'",
    "lib/gitlab/middleware/read_only.rb:18:in `call'",
    "lib/gitlab/middleware/same_site_cookies.rb:27:in `call'",
    "lib/gitlab/middleware/basic_health_check.rb:25:in `call'",
    "lib/gitlab/middleware/handle_ip_spoof_attack_error.rb:25:in `call'",
    "lib/gitlab/middleware/request_context.rb:23:in `call'",
    "config/initializers/fix_local_cache_middleware.rb:9:in `call'",
    "lib/gitlab/metrics/requests_rack_middleware.rb:60:in `call'",
    "lib/gitlab/middleware/release_env.rb:12:in `call'"
  ],
  "queue_duration_s": 0.005428,
  "correlation_id": "1234567890",
  "meta.user": "auser",
  "meta.project": "auser-group/conan",
  "meta.root_namespace": "auser-group",
  "meta.caller_id": "/api/:version/packages/conan/v1/conans/:package_name/:package_version/:package_username/:package_channel/upload_urls"
}