Bug #8541: Open3.popen3 creates a broken stdout pipe

• Status: Rejected
• Assignee: -
• Target version: -
• ruby -v: ruby 2.0.0p195 (2013-05-14 revision 40734) [universal.x86_64-darwin13]
• Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN

[ferrous26 (Mark Rada)]

When I create a subprocess using Open3, the stdout pipe that is returned does allow reading.

Using the sample code provided, Ruby will block indefinitely waiting to read from the subprocess, though the subprocess has printed out to standard output.

If you change the test script to print/read from standard error instead, then everything works.

[ferrous26 (Mark Rada)]

Note in the test script, the subprocess must continue running in order for the bug to manifest.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Rejected

Use $stdout.flush after puts, or $stdout.sync = true before puts.