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

Solution 1

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.

Solution 2

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.

Solution 3

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.

Comments

[Bart VdA]

The amount of files in the temp folders of the agent are limited. Is this the temp folder you are referring to?

[Alex M]

Was exactly this. The temp folder for the user running the build (C:\Users\USERNAME\AppData\Local\Temp) was having more than 65535 files.

[Bart VdA]

Will give it a try, for now I just removed the signing on the project. Also solved it as a workaround :-)