gradlew gemPush with JRuby 9.4.3.0

gradle.txt

./gradlew gemPush

> Task :gemPush
Executing: `java org.jruby.Main -rjars/setup -S gem push /path/to/embulk-filter-calc/build/gems/embulk-filter-calc-0.2.1.pretest-java.gem --verbose`
    with working directory at: /path/to/embulk-filter-calc/build/gems
    with classpath: [ /Users/user/.gradle/caches/modules-2/files-2.1/org.jruby/jruby-complete/9.4.3.0/7324205fb4ad1b40d6aee488db6e72918f397ad4/jruby-complete-9.4.3.0.jar ]
Pushing gem to https://rubygems.org...
POST https://rubygems.org/api/v1/gems
ERROR:  While executing gem ... (IOError)
    Broken pipe
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/net/http.rb:1602:in `block in transport_request'
        org/jruby/RubyKernel.java:1308:in `catch'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/net/http.rb:1600:in `transport_request'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/net/http.rb:1573:in `request'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/request.rb:222:in `perform_request'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/request.rb:154:in `fetch'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/remote_fetcher.rb:309:in `request'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/gemcutter_utilities.rb:247:in `request_with_otp'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/gemcutter_utilities.rb:105:in `rubygems_api_request'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/commands/push_command.rb:89:in `send_push_request'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/commands/push_command.rb:81:in `send_gem'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/commands/push_command.rb:66:in `execute'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/command.rb:323:in `invoke_with_build_args'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/command_manager.rb:185:in `process_args'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/command_manager.rb:149:in `run'
        uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/gem_runner.rb:51:in `run'
        uri:classloader:/META-INF/jruby.home/bin/jgem:21:in `<main>'
        org/jruby/RubyKernel.java:1105:in `load'
        uri:classloader:/META-INF/jruby.home/bin/gem:4:in `<main>'

> Task :gemPush FAILED

FAILURE: Build failed with an exception.