Current behaviour
We have passenger 6.0.22 installed in our Dockerfile on Ruby 3.3.3-bullseye via

apt-get install -y nginx libnginx-mod-http-passenger

We don't have the passenger gem itself in our Gemfile. The PhusionPassenger constant get's injected by the nginx module.

At startup ddtrace complains with this warning:

WARN -- ddtrace: [ddtrace] Enabling the profiling "no signals" workaround because an incompatible version of the passenger gem is installed. Profiling data will have lower quality.To fix this, upgrade the passenger gem to version 6.0.19 or above.

Expected behaviour
ddtrace should look at the PhusionPassenger::VERSION_STRING constant instead of Gem.loaded_specs['passenger'].version:

So maybe these lines could be

      private_class_method def self.incompatible_passenger_version?
        if defined?(PhusionPassenger)
          PhusionPassenger::VERSION_STRING < Gem::Version.new('6.0.19')
        else
          true
        end
      end

Steps to reproduce

• Remove passenger gem from Gemfile if present
• Install Passenger in nginx via libnginx-mod-http-passenger
• Start the rails server in passenger, then you should see the warning

Environment

• datadog version: ddtrace 1.23.1
• Ruby version: 3.3.3
• Operating system: Debian bullseye
• Relevant library versions: