Doesn't install on Node.js 16 (macOS only)

[spencerwilson]

Describe the bug
On 7682aab aka v0.2.0, npm install on Node.js 16+ (the "Current" major version; will become "Active" LTS on 2021-10-26) fails during installation of the transitive dependency dd-trace:

  CXX(target) Release/obj.target/metrics/packages/dd-trace/src/native/metrics/Collector.o
In file included from ../packages/dd-trace/src/native/metrics/Collector.cpp:1:
In file included from ../packages/dd-trace/src/native/metrics/Collector.hpp:6:
In file included from ../packages/dd-trace/src/native/metrics/Object.hpp:3:
In file included from ../../nan/nan.h:56:
In file included from /Users/ssw/Library/Caches/node-gyp/16.0.0/include/node/node.h:63:
In file included from /Users/ssw/Library/Caches/node-gyp/16.0.0/include/node/v8.h:30:
/Users/ssw/Library/Caches/node-gyp/16.0.0/include/node/v8-internal.h:452:38: error: no template named 'remove_cv_t' in namespace 'std'; did you mean 'remove_cv'?
            !std::is_same<Data, std::remove_cv_t<T>>::value>::Perform(data);
                                ~~~~~^~~~~~~~~~~
                                     remove_cv
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/type_traits:776:50: note: 'remove_cv' declared here
template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_cv
                                                 ^
1 error generated.
make: *** [Release/obj.target/metrics/packages/dd-trace/src/native/metrics/Collector.o] Error 1

To Reproduce
Steps to reproduce the behavior:

1. npm install using Node.js 16.x on any platform

Expected behavior
Installs without error

Additional context

I confirmed that the package can successfully be installed after applying

diff --git a/package.json b/package.json
index 53323be..7d567f1 100644
--- a/package.json
+++ b/package.json
@@ -71,6 +71,6 @@
     "@opentelemetry/core": "^0.16.0",
     "@opentelemetry/resources": "^0.16.0",
     "@opentelemetry/tracing": "^0.16.0",
-    "dd-trace": "^0.21.0"
+    "dd-trace": "^0.35.0"
   }
 }

but under that patch, 35 of the 45 non-skiped tests fail:

  35 passing (242ms)
  2 pending
  10 failing

For more info on the dd-trace bug, see DataDog/dd-trace-js#1388.

[spencerwilson]

Workaround: Rather than sending trace data from my Node.js process directly to Datadog, I'm probably gonna export it via @opentelemetry/exporter-collector-grpc to an OpenTelemetry Collector configured to run the Datadog exporter. I also notice that this'll happily put us in compliance with the guidance added in DataDog/documentation#9824:

Datadog recommends you use the OpenTelemetry Collector Datadog exporter in conjunction with OpenTelemetry tracing clients [, with the language-specific exporters as a secondary option]

P.S. Thanks @ericmustin for your effort to bring OTel support to Datadog! As a customer, I appreciate it.

[ericmustin]

@spencerwilson 👋 hope all is well. apologies for the state of affairs of this repo, it is indeed a bit out of date with latest node and also just in general with latest opentelemetry-js. For context, we're working on adding OTLP Support directly to the datadog-agent, which would preclude the need for these helper libs in every language. In the meantime the suggested setup is to use the opentelemetry-collector (contrib flavor) and the datadogexporter.