Fix tools tests

[jgraham]

No description provided.

[gsnedders]

Also ignore errors that occur when trying to close the file handles.

Can you at least say why this is needed, @jgraham?

[jgraham]

Because we were seeing Broken Pipe Error sometimes. But also because any error during cleanup seems like it should at worst be a warning; the worst that can happen is we leak a file handle (which admittedly isn't great), but given that file operations are intrinsically unreliable, but failure to close a file shouldn't be fatal, I'm not sure what would be better.