From: Eric Hodel <drbrain@...7.net>
Date: 2011-01-25T02:32:36+09:00
Subject: Re: FileUtils writing to stderr

On Jan 24, 2011, at 5:25, "Mark L." <marcuslamb@yahoo.com> wrote:

> Hi there,
> 
> I'm having a few issues with FileUtils writing stuff to stderr when no error has occurred. For example I might have the following simple
> Rakefile:
> 
> require 'rake'
> task :clean do
>  rm_rf 'test'
> end

Note that rake's rm_rf is not exactly FileUtils' rm_rf

> When I run
> 
> rake clean 2> err
> 
> In the err file I see:
> 
> 'rm -rf test'
> 
> I would expect this to be sent to stdout rather than err.

Why? I expect informational messages on stderr. This way rake's messages don't interfere with a rake user's output. By having rake's messages on stderr a rake task author can write tasks that can be piped to other commands.

rake email | sendmail # for example

(Yes, rake currently outputs a message on stdout. I have fixed that in trunk.)

> The problem that I have is that I am trying to detect a rake failure from within ant. Rake doesn't seem to return the correct error code so I was testing for failure by detecting if anything was written to stderr.

You should query $?, not stderr. Rake should be behaving like a standard unix command. 

> My ant task would thus look something like this:
> 
> <target name="rake">
>  <exec executable="rake" failonerror="true" errorproperty="rake.err">
>    <arg value="clean">
>  </exec>
>  <fail if="rake.err" message="Rake failed with: ${rake.err}"/>
> </target>
> 
> This works fine except when I try to use the FileUtils methods. rm_rf causes it to fail as does mkdir_p.
> 
> Any suggestions?

AFAIK rm -rf and mkdir -p always exit 0.

What is your rake task that exits 0 improperly?