Error when redirecting stdout and stderr of powershell script

Question

The script runs fine when stdout/stderr are not redirected.

When I add both stderr and stdout redirection, I getg the following error: How can I avoid it?

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed

  0 19.4M    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
 81 19.4M    0     0   81 15.9M      0  54.5M --:--:-- --:--:-- --:--:-- 55.8M
100 19.4M    0     0  100 19.4M      0  14.2M  0:00:01  0:00:01 --:--:-- 14.3M
100 19.4M    0     0  100 19.4M      0  8428k  0:00:02  0:00:02 --:--:-- 8454k
100 19.4M    0     0  100 19.4M      0  5924k  0:00:03  0:00:03 --:--:-- 5937k
100 19.4M    0     0  100 19.4M      0  4567k  0:00:04  0:00:04 --:--:-- 4575k
100 19.4M    0    50  100 19.4M     10  4291k  0:00:04  0:00:04 --:--:--  835k
out-lineoutput : The OS handle's position is not what FileStream expected. Do not use a handle simu
ltaneously in one FileStream and in Win32 code or another FileStream. This may cause data loss.
    + CategoryInfo          : NotSpecified: (:) [out-lineoutput], IOException
    + FullyQualifiedErrorId : System.IO.IOException,Microsoft.PowerShell.Commands.OutLineOutputCom 
   mand

Answer 1

Lee Holmes (one of the senior developers on the powershell team) covers this here in a blog post:

http://www.leeholmes.com/blog/WorkaroundTheOSHandlesPositionIsNotWhatFileStreamExpected.aspx

This is bug in PowerShell v1.0, and happens when:

• a PowerShell command generates both regular and error output
• you have used cmd.exe to redirect the output to a file
• you have used cmd.exe to merge the output and error streams

There is a workaround.

-Oisin