Liquidsoap cannot write data to host: Broken pipe in write() error

My liquidsoap audio stream has just started to stop playing with this error message every few requests.

Error while sending data: could not write data to host: Broken pipe in write()!

It seems to fix itself pretty quickly and I can restart playing, but the interruption is annoying.

The liquidsoap script I'm using is pretty basic and pulls some songs from a database.

Here is the script.

def apply_metadata(m) =
  title = m["title"]
  artist = m["artist"]
  log("Now playing: #{title} by #{artist}")
end

def apply_track(m) =
  get_process_lines("curl http://localhost/api/v1/liquidsoap/playing")
  log("actually playing")
end

def get_request() =
  uri = list.hd(default="",get_process_lines("curl http://localhost/api/v1/liquidsoap/next"))
  request.create(uri)
end

def my_safe(s) =
  security = sine()
  fallback(track_sensitive=false,[s,security])
end

s = request.dynamic(id="s",timeout=60.0,get_request)
s = on_metadata(apply_metadata,s)
s = on_track(apply_track,s)
s = crossfade(s)
s = my_safe(s)

# We output the stream to an icecast
# server, in ogg/vorbis format.
output.icecast(
  %mp3(id3v2=true,bitrate=128,samplerate=44100),
  host = "localhost",
  port = 8000,
  mount = "ogr",
  s
)

Here is the liquidsoap log.

2018/09/15 17:23:04 [lang:3] Now playing: La Sirena by Banyan
2018/09/15 17:23:17 [lang:3] actually playing
2018/09/15 17:23:17 [ogr:3] Metadata update may have failed with error: 400, Bad Request (HTTP/1.0)
2018/09/15 17:23:17 [clock.wallclock_main:2] We must catchup 13.88 seconds!
2018/09/15 17:23:17 [ogr:2] Error while sending data: could not write data to host: Broken pipe in write()!
2018/09/15 17:23:17 [ogr:3] Closing connection...
2018/09/15 17:23:17 [ogr:3] Will try to reconnect in 3.00 seconds.
2018/09/15 17:23:18 [clock.wallclock_main:2] We must catchup 7.12 seconds (we've been late for 100 rounds)!
2018/09/15 17:23:21 [ogr:3] Connecting mount ogr for source@localhost...
2018/09/15 17:23:21 [ogr:3] Connection setup was successful.

I'm not sure why it has started doing this as it's been working perfectly for a long time previously and I've made no changes.

Any suggestions or help much appreciated as my understanding of liquidsoap is very basic.

Thanks.