From: ngotogenome@...
Date: 2015-07-14T06:03:18+00:00
Subject: [ruby-core:69963] [Ruby trunk - Bug #11350] [Open] When Process.exec failed, redirections were still changed and not restored

Issue #11350 has been updated by Naohisa Goto.

Status changed from Feedback to Open
Assignee deleted (Nobuyoshi Nakada)

> Consider to create a child process using ::spawn or Kernel#system if this is
> not acceptable.

I think so, and I agree this is a spec.

I think the documentation should be added about the risk of ASYNC BUG when redirecting FDs that Ruby timer thread internally uses.

PS.
It seems that Japanese documentation of Process.exec does not describe about the limitation. (but this is not a bug of Ruby itself)
http://docs.ruby-lang.org/ja/2.2.0/class/Process.html#S_EXEC

----------------------------------------
Bug #11350: When Process.exec failed, redirections were still changed and not restored
https://bugs.ruby-lang.org/issues/11350#change-53395

* Author: Naohisa Goto
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: 
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
When Process.exec failed, redirections of file descriptors were changed and not restored.

When redirecting fd 3 or 5, ASYNC BUG occurred as below.

~~~
$ ruby -e 'begin; Process.exec("/does_not_exist", "arg", { 3=>["/dev/null", "w"]}); rescue Errno::ENOENT => e; $stdout.print "stdout: ", e.inspect, "\n"; $stderr.print "stderr: ", e.inspect, "\n"; end'
[ASYNC BUG] consume_communication_pipe: read

EBADF

ruby 2.3.0dev (2015-07-13) [sparc64-solaris2.10]

[NOTE]
You may have encountered a bug in the Ruby interpreter or extension libraries.
Bug reports are welcome.
For details: http://www.ruby-lang.org/bugreport.html

stdout: #<Errno::ENOENT: No such file or directory - /does_not_exist>
stderr: #<Errno::ENOENT: No such file or directory - /does_not_exist>Abort
~~~

~~~
$ ruby -e 'begin; Process.exec("/does_not_exist", "arg", { 5=>["/dev/null", "w"]}); rescue Errno::ENOENT => e; $stdout.print "stdout: ", e.inspect, "\n"; $stderr.print "stderr: ", e.inspect, "\n"; end'
[ASYNC BUG] consume_communication_pipe: read

EBADF

ruby 2.3.0dev (2015-07-13) [sparc64-solaris2.10]

stdout: [NOTE]
You may have encountered a bug in the Ruby interpreter or extension libraries.
Bug reports are welcome.
For details: http://www.ruby-lang.org/bugreport.html

#<Errno::ENOENT: No such file or directory - /does_not_exist>
stderr: #<Errno::ENOENT: No such file or directory - /does_not_exist>Abort
~~~



When redirecting fd 1 or 2 to /dev/null, stdout or stderr is still redirected to /dev/null and the printed contents are not shown.

~~~
% ruby -e 'begin; Process.exec("/does_not_exist", "arg", { 1=>["/dev/null", "w"]}); rescue Errno::ENOENT => e; $stdout.print "stdout: ", e.inspect, "\n"; $stderr.print "stderr: ", e.inspect, "\n"; end'
stderr: #<Errno::ENOENT: No such file or directory - /does_not_exist>
~~~

~~~
% ruby -e 'begin; Process.exec("/does_not_exist", "arg", { 2=>["/dev/null", "w"]}); rescue Errno::ENOENT => e; $stdout.print "stdout: ", e.inspect, "\n"; $stderr.print "stderr: ", e.inspect, "\n"; end'
stdout: #<Errno::ENOENT: No such file or directory - /does_not_exist>
~~~

All of the above are observed both on x86_64 Linux and sparc Solaris.

Is this spec or bug?




-- 
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