"File is being used by another process"

[sa2ajj]

Per discussion on ​IRC, there's an error while uploading a directory on Windows 8.

Currently I see two options (both seem to be bad):

• the file is not closed in source:/slave/buildslave/commands/transfer.py#L219​ (can't reproduce this under Linux)
• the temporary file name is not unique (there could be three builds running on the build slave in question)

I hope "brson" will provide a bit more information about the second option and I'll try to check the first one once I have a Windows machine to test.

[sa2ajj]

The test coverage is collected under Linux, so I can't really say if this particular part of code is tested under Windows (under Linux it gets tested).

[sa2ajj]

"brson" said in a Rust related ​ticket that when they run only one build on their EC2 instance, the problem does not manifest.

So it looks like we might have a problem with temporary names, but I really do not know how to approach it.

[dustin]

The mkstemp implementation (​https://hg.python.org/cpython/file/2.7/Lib/tempfile.py#l230) seems pretty straightforward..