OverwriteReadOnlyFiles property ,error MSB3021

Question

this is the problem im having :

The error message

error MSB3021: Unable to copy file "<filename>" to "<output location>". Access to the path '<output location>' is denied

occurs when the MSBuild Copy task cannot overwrite an existing read-only file.

Typically in Team Build this error will occur because (a) there seems to be an issue in MSBuild where the same file can get included more than once in the list of files to get copied, and (b) these files will typically be read-only in a Team Build since they are retrieved from version control (and not checked out). The workarounds for the issue depend on the version of Team Build (and MSBuild) you are using.

i found this solution:

Team Build 2008 / MSBuild 3.5
In MSBuild 3.5, an OverwriteReadOnlyFiles property was added that can be set to true to allow Copy tasks involved in the build process to overwrite read-only files in cases like the one outlined here. As such, a third workaround is possible in Team Build 2008 / MSBuild 3.5. Note that this workaround will only work for projects that use the 3.5 version of Microsoft.Common.targets - because of the multi-targeting feature available in MSBuild, this will not necessarily be every project built by Team Build 2008.

To set the OverwriteReadOnlyFiles property to true globally, you can either:

Add the text "/p:OverwriteReadOnlyFiles=true" to TfsBuild.rsp for your build definition, or Add the following property group to TfsBuild.proj for your build definition.

<PropertyGroup>
  <CustomPropertiesForBuild>OverwriteReadOnlyFiles=true</CustomPropertiesForBuild>
</PropertyGroup>

Can someone Guide me on how to implement this solution on TFS 2010 on my build ?

i don't know where :

TfsBuild.rsp

or

TfsBuild.proj

are located and how i can add the mentioned suggestions

Why do you need to overwrite files under source control as part of a build? That is a smell to me that something is not quite write... — MrHinsh - Martin Hinshelwood

Dylan Smith Dylan Smith · Accepted Answer · 2014-06-17T02:21:47

TFSBuild changed significantly in TFS 2010, it is no longer MSBuild based and is instead Workflow based. There is no longer a TfsBuild.proj file.

If you are trying to overwrite read-only files, you are possibly doing something that is not according to best practices (as MrHinsh mentioned in the comments). If you are sure that what you are doing is appropriate then you either need to turn-off the read-only flag, or use a copy method that is able to ignore the read-only flag.

OverwriteReadOnlyFiles property ,error MSB3021

1 Answers