Sync on linux: /dev/stdout: invalid argument

[benbarbour]

I'm seeing this every time I call .Sync() on linux (Ubuntu 18.04.3) when writing to stdout or stderr. Specifically, I'm getting an *os.PathError with the message "sync /dev/stdout: invalid argument". Should I open a new bug?

Looks a lot like #328, but I don't see a mention of a PathError there, so I opened a new bug.

[prashantv]

This is related to #370 -- the console driver does not support fsync, hence the errors.

We don't want to ignore all errors for stdout/stderr, since they may be attached to a file which does support fsync, in which case any error would be a real error we shouldn't ignore

Detecting terminals won't work because it can happen in other cases too (e.g., pipes).

Perhaps we can ignore EINVAL in zap.

[benbarbour]

Ok, so it is the same bug. This can probably be closed then.

Maybe I'll just ignore that exact os.PathError (for /dev/std*) in my code for now.

[prashantv]

Closing as suggested, but open to ideas around ignoring EINVAL for stdout/stderr.