Gem provider does not honour system wide gem sources settings

When I run the following code:
package

{ 'random-client': ensure => installed, provider => 'gem', source => 'http://example.net:2000', }

with puppet apply <filename.pp> it fails to install the gem.

It fails because it tries to install the gem from rubygems.org and it will not find the gem there ever. I have set gem sources both in ~/.gemrc and in /etc/gemrc but these files does not get read by puppet. The documentation suggests that adding the source property will get it to use the correct repository but this does not work either. The puppet agent version is v4.2.1gem

This is the error message:
Error: Execution of '/usr/bin/gem install --source http://example.net:2000 random-client' returned 1: ERROR: Could not find a valid gem 'random-client' (>= 0) in any repository
ERROR: While executing gem ... (Gem::RemoteFetcher::FetchError)
Errno::ETIMEDOUT: Connection timed out - connect(2) (https://rubygems.org/latest_specs.4.8.gz)
Error: /Stage[main]/Main/Package[random-client]/ensure: change from absent to present failed: Execution of '/usr/bin/gem install --source http://example.net:2000 random-client' returned 1: ERROR: Could not find a valid gem 'random-client' (>= 0) in any repository
ERROR: While executing gem ... (Gem::RemoteFetcher::FetchError)
Errno::ETIMEDOUT: Connection timed out - connect(2) (https://rubygems.org/latest_specs.4.8.gz)