Using rsync to copy large file sets, but getting some errors.

Here is the exact command output along with the logs.

```
cyclops@Thom:~$ rsync Desktop/Star\ Trek-\ Discovery /Volumes/Keybase\ \(cyclops\)/private/titanshadow\,shortcut53/
building file list ...
17 files to consider
Star Trek- Discovery/
Star Trek- Discovery/Season 01/
Star Trek- Discovery/Season 01/Star Trek Discovery - S01E10 - Despite Yourself - WEBDL-720p.mkv
1.05G 100% 3.76MB/s 0:04:26 (xfer#1, to-check=14/17)
Star Trek- Discovery/Season 01/Star Trek Discovery - S01E11 - The Wolf Inside - WEBDL-720p.mkv
rsync: writefd_unbuffered failed to write 32768 bytes [sender]: Broken pipe (32)
rsync: write failed on "/Volumes/Keybase (cyclops)/private/titanshadow,shortcut53/Star Trek- Discovery/Season 01/Star Trek Discovery - S01E11 - The Wolf Inside - WEBDL-720p.mkv": Input/output error (5)
rsync error: error in file IO (code 11) at /BuildRoot/Library/Caches/com.apple.xbs/Sources/rsync/rsync-47/rsync/receiver.c(268) [receiver=2.6.9]
rsync: connection unexpectedly closed (896 bytes received so far) [generator]
rsync error: error in rsync protocol data stream (code 12) at /BuildRoot/Library/Caches/com.apple.xbs/Sources/rsync/rsync-47/rsync/io.c(453) [generator=2.6.9]
rsync: connection unexpectedly closed (64 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at /BuildRoot/Library/Caches/com.apple.xbs/Sources/rsync/rsync-47/rsync/io.c(453) [sender=2.6.9]
```

my log id: fd82e66793987aba3a257a1c

Start by reproducing the exact rsync command and reviewing the Keybase logs for id fd82e66793987aba3a257a1c. Use the reported receiver.c(268) and io.c(453) errors as entry points, then determine the cause of the file I/O failure and document or verify a resolution.

Written by the indexing model from the issue text.