traceparent header missing trace-flags

[benjaminrigaud]

How do you use Sentry?

Sentry SaaS (sentry.io)

SDK version

4.4.0+

Steps to reproduce

• Receiving API requests from partners using Sentry PHP SDK
  • These requests contains an incomplete traceparent header like: 00-f3e67297c2a2426c93e9453af787103d-58738da11f564cf4
• ddtrace is unable to parse this traceparent and is logging an error that gets reported to our Sentry ♻️

These errors appeared at the start of February: one week after the Sentry PHP SDK 4.4.0 release that introduced the support for traceparent header.

Expected result

Valid traceparent headers: 00-f3e67297c2a2426c93e9453af787103d-58738da11f564cf4-{XX}

Actual result

Invalid traceparent header: 00-f3e67297c2a2426c93e9453af787103d-58738da11f564cf4

It is missing the trace-flags part at the end.
https://www.w3.org/TR/trace-context/#examples-of-http-traceparent-headers

Is it coming from PropagationContext::toW3CTraceparent?

https://github.com/getsentry/sentry-php/pull/1680/files#diff-409ef5376d2e7e91792b0d68cac9d9f8dd1d078d25346e63462a652d789adf9bR73

[cleptric]

I was under the impression that the sampled flag was optional to delegate the sampling decision to the receiving service. But I was wrong, it will be fixed in #1713.

[cleptric]

Fixed in 4.6.1.