MSB5003: Failed to create a temporary file.

Question

All of a sudden we are getting this error on the build computer.  We have searched the forums and followed other resolutions (delete the Temp directory) but still it continues.
The full error message:
[Any CPU/Debug] C:\Windows\Microsoft.NET\Framework\v3.5\Microsoft.CSharp.targets(135,9): error MSB6003: The specified task executable "Csc.exe" could not be run.
MSB5003: Failed to create a temporary file. Temporary files folder is full or its path is incorrect. The file exists.
Any ideas what to try next?

Answer 1

Not permissions.  Not TEMP path name. 
After some research we ran Process Monitor during the build.  Turns out we used up all of the temporary file names... LOL! 
Tmp file names in Vista, and maybe others, have the format tmp####.tmp, where #### is 0x0000 to 0xffff.   When we looked in the Temp directory we found over 65,000 TMP files.  We are guessing that CSC creates these files but does not remove them.  After so many thousands of builds, we ran out of names.  We thought they were gone when we ran Disk Cleanup, but MSBUILD uses the administrator account while we were cleaning from a user account.
Might be nice if CSC deleted it's TMP files...
There ya go, add that to your bag of tricks... :)