Marc Alff

Thanks for the initial report and investigations. From the previous comments, in particular: ``` Gcc 9 and 10 have that part changed to call std::get explicitly, so it won't have...

@lalitb The issue originally reported seem out of date now. Could this be closed ?

/easycla

> For example, `${API_KEY}` is a environment variable substitution, while `${1API_KEY}` and `${API_$KEY}` are just strings. I agree.

I don't think this will work. Whether the original yaml text contains `\x7b` or `{`, the yaml parser will return a scalar that contains `{` anyway, so code that inspects...

From: https://github.com/open-telemetry/oteps/blob/main/text/0225-configuration.md#environment-variable-substitution Pointing to: https://opentelemetry.io/docs/collector/configuration/#environment-variables > Use $$ to indicate a literal $. For example, representing $DataVisualization would look like the following: To be consistent with the collector, we can...

cc @jack-berg

> Can you add a changelog entry? Thanks! Done.

> Ping @open-telemetry/configuration-maintainers (otherwise we are good to go) @jack-berg is part of configuration-maintainers, and already approved. Not sure how many approvals are needed.

PS: I am aware of this related issue: * https://github.com/open-telemetry/opentelemetry-specification/issues/3324 which is not a duplicate. #3617 is about adding predicates to filter out `Meter`s as a whole, while #3324 is...