Hi all,

I maintain a small OCaml program that generates some data, writes it to a
temporary file and creates another process, which then reads that temporary
file. Recently, I've received a few reports from users that the program
generates an empty file when it should not. All of the affected users run
either 64bit Win7 or Win10. I have access to one of those users' machines,
and I can reproduce the issue consistently, however I'm not able to
reproduce the issue on any other machine.

The file io part looks something like following:
let oc = open_out_bin file in
output_string oc s;
close_out oc

The string "s" has non-zero size. The out channel has non-zero length and
doing Unix.stat on the file after its closed shows non-zero size. However,
both the newly created process and Windows see the file as empty after the
program exits.

Any ideas on what might be happening?

Thanks,
Dmitriy