>>16This is a "known issue".
Basically, on return, the system flushes all buffers. in case flushing errors-out (the libc fails to write its internal buffers to the kernel device) it can't report an error and ignores it.
GNU coreutils solve this by having an onexit-function doing the cleanup and reporting errors in case something fails.
However, _exit is usually used across sbase which doesn't call onexit-functions and generally speaking, onexit-functions are a pain in the ass to take care of.
Another idea was to have a efclose-function which closes stdin and stdout at the end and reports an error in case it fails. However, it's not simple to take care of that across sbase either. In the end, the conclusion was that this is a more or less non-priority issue.
This has been kept it mind, same with echo, but not reflected on it as there were more important issues.
If you have any ideas, let it be known.