OK, now I think I have it. No warnings or errors:
Processing file "OpusTestStreamChris.opus"...
New logical stream (#1, serial: 00000001): type opus
Encoded with libopus 1.1
User comments section follows...
ENCODER=opusenc from opus-tools 0.1.8
ENCODER_OPTIONS=--serial 1 --quiet --comp 0 --ignorelength
Opus stream 1:
Pre-skip: 316
Playback gain: 0 dB
Channels: 1
Original sample rate: 44100Hz
Packet duration: 20.0ms (max), 20.0ms (avg), 20.0ms (min)
Page duration: 1000.0ms (max), 510.0ms (avg), 20.0ms (min)
Total data length: 9951 bytes (overhead: 9.51%)
Playback length: 0m:00.999s
Average bitrate: 79.61 kb/s, w/o overhead: 72.04 kb/s
Logical stream 1 ended
New logical stream (#2, serial: 00000002): type opus
Encoded with libopus 1.1
User comments section follows...
ENCODER=opusenc from opus-tools 0.1.8
ENCODER_OPTIONS=--serial 2 --quiet --comp 0 --ignorelength
Opus stream 2:
Pre-skip: 316
Playback gain: 0 dB
Channels: 1
Original sample rate: 44100Hz
Packet duration: 20.0ms (max), 20.0ms (avg), 20.0ms (min)
Page duration: 1000.0ms (max), 510.0ms (avg), 20.0ms (min)
Total data length: 9951 bytes (overhead: 9.51%)
Playback length: 0m:00.999s
Average bitrate: 79.61 kb/s, w/o overhead: 72.04 kb/s
Logical stream 2 ended