Build error when signing with snk key

Question

Build error is occurring since using Visual Studio 2015. When building in Visual Studio 2015 this is occurring rarely. When building in TeamCity this occurs very often.

[Error in Visual Studio 2015]

• Error extracting public key from file 'CompanyName.snk': The process cannot access the file 'C:\Users\UserName\AppData\Local\Temp\tmp2FF6.tmp' because it is being used by another process. CompanyName.Project.DAL D:\Projecten\CompanyName\Repository\Source\Components\CompanyName.Project.DAL\vbc

http://i.stack.imgur.com/hKbbe.png

[Error in TeamCity]

• CSC error CS7027: Error signing output with public key from file 'CompanyName.snk' -- The process cannot access the file 'C:\BuildAgents\Gamma\temp\buildTmp\tmpD91D.tmp' because it is being used by another process.

http://i.stack.imgur.com/rbgHx.png

Answer 1

Try to clean up the temp folder that is used by the build. I have seen different types of problems when the temp folder has lots of files.

Some of the tools are using GetTempFileName and they will get errors when temp has a lots of files

The GetTempFileName method will raise an IOException if it is used to create more than 65535 files without deleting previous temporary files.

Answer 2

I just had the same problem. In Visual Studio 2015, I fixed it using the following steps:

1. Go to Tools > Options
2. From the Options dialog, select "Projects and Solutions > Build and Run"
3. Set the "maximum number of parallel project builds" to 1

+1 to @stukselbax for getting me on the right track Also got help from this link

Answer 3

It started for me when I moved the Resharper Cache to System Temp. When I moved it back to the Solution folder, the problem went away, and I could build again.

Answer 4

This is probably an instance of this issue with Roslyn compiler. The workaround would be adding

<UseSharedCompilation>False</UseSharedCompilation>

under any <PropertyGroup> node in .csproj file.

Answer 5

I know it's been a while since this was asked but as I use SO for my own reference and I had this problem too I wanted to share my solution.

.snk files are for signing a project. You might need to make a new one.

• Right click on your project, select properties.
• Click on Signing.
• Click the checkbox beside "Sign the assembly".
• On the dropdown labelled "Choose a strong name key file" click new.
• Fill in the dialog box as you wish noting particularly the Key file name. When you press ok, this will generate a new .snk file.
• Save the project and rebuild.
• This will use the new .snk in your project and will resolve the error.

Hope this helps.