WARN FilenoUtil : Native subprocess control requires open access to the JDK IO subsystem

[gshields]

irb
2020-11-21T12:02:38.345-08:00 [main] WARN FilenoUtil : Native subprocess control requires open access to the JDK IO subsystem
Pass '--add-opens java.base/sun.nio.ch=org.jruby.dist --add-opens java.base/java.io=org.jruby.dist' to enable.
irb(main):001:0>

C:\Users\ghs>jruby --version
jruby 9.2.13.0 (2.5.7) 2020-08-03 9a89c94 OpenJDK 64-Bit Server VM 15.0.1+9-18 on 15.0.1+9-18 +jit [mswin32-x86_64]
on windows 10 ver 20H2

-->

Environment Information

Provide at least:

• JRuby version (jruby -v) and command line (flags, JRUBY_OPTS, etc)
• Operating system and platform (e.g. uname -a)

Other relevant info you may wish to add:

• Installed or activated gems
• Application/framework version (e.g. Rails, Sinatra)
• Environment variables

Expected Behavior

• Describe your expectation of how JRuby should behave, perhaps by showing how CRuby/MRI behaves.
• Provide an executable Ruby script or a link to an example repository.

Actual Behavior

• Describe or show the actual behavior.
• Provide text or screen capture showing the behavior.

[headius]

This is likely due to the launcher not being updated on Windows recently. That has other issues filed for it but I don't remember the issue numbers offhand.

You can avoid this warning by adding those flags to the JAVA_OPTS environment variable, either in the system settings or at a command line like this:

set JAVA_OPTS="--add-opens java.base/sun.nio.ch=org.jruby.dist --add-opens java.base/java.io=org.jruby.dist"

We will get a new JRuby release out soon with an updated jruby.exe launcher. cc @enebo

[enebo]

This is fixed with new jruby launcher build.