Command copy exited with code 4 when building - Vi

Question

Every now and then when I build my solution here (with 7 projects in it) I get the dreaded 'Command copy exited with code 4' error, in Visual Studio 2010 Premium ed.

This is because of the post-build event not being able to go through.

Here's what solves the problem, temporarily

• Sometimes: A restart of Visual Studio and I'm able to build the solution
• Sometimes: Both a restart of Visual Studio and my file manager of choice (Q-Dir 4.37) solves it.

Here's what the post-build event looks like:

xcopy "$(SolutionDir)Solution Items\References\*.dll" "$(TargetDir)" /Y

When you get the command copy exited with code [insert value] error, it's normally because of the following:

• read / write permissions
• missing files
• wrong directories

However - obviously at times when I build the solution, there's no problem.

FYI, I uninstalled ReSharper 5.1.1 two weeks ago and Visual Studio's been giving me some errors since then (among them not being able to debug). I re-installed Visual Studio and it's working better since then, but still get this problem. Could it have to do with some ReSharper stuff being somewhere?

Have you had the same problem and solved it? Or do you have any possible solution to it?

Cheers.

Answer 1

I've invariably found this to be a file locking issue. Code 4 is Cannot Access File. One partial solution I found is to use the /C option for xcopy (which continues on error). Not really a solution but mostly it has stopped my builds from failing.

Another solution which only works on 32 bit is to use the unlocker tool to release the windows handles on the file before the copy.

Edit: I've just realised that it works under 64 bits too.

Answer 2

In case the post build event contains copy/xcopy command for copying build output to some directory(which usually is the most common post build operation) the problem can occur in case the full directory path either of source or target destinations contain folder names which include spaces. Remove space for the directory name(s) and try.

Answer 3

While /C may ignore errors, it might not be the real solution as there could be files that MUST be copied in order for the build to be successful.

The most common issue is the missing quotes around the pre-defined command tags (such as $TargetDir). When one creates various branches and paths in code or TFS, there is a very high chance for this to occur.

Sometimes if the file is read only, it will cause issues too. Add the /R option to allow read only files to be copied over. You can find list of available options at:

http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/xcopy.mspx?mfr=true

Another possible issue is that the underlying folder cannot be accessed. If so, trying performing "start xcopy" instead of "xcopy". This will open another command window but with admin priveleges.

Answer 4

I faced the same issue in case of XCOPY after build is done. In my case the issue was happening because of READ-ONLY permissions set on folders.

I added attrib -R command before XCOPY and it solved the issue.

Hope it helps someone!

Answer 5

I had the same error with xcopy in connection with the Test Engine. I am using VisualStudio Professional 2013. By default Test -> Test Settings -> Keep Test Execution Engine Running seems to be the reason for my error code 4 with xcopy. Switching it off solved the problem. The execution engine seems to keep hold on some .dlls.

Answer 6

I got this error because the user account that TFS Build Service was running under did not have permissions to write to the destination folder. Right-click on the folder-->Properties-->Security.