Error using scaletempo with audiomixer

Application Development
1

I have a pipeline created programmatically in C as:

gst-launch-1.0 \
     audiomixer name=mix ! audioconvert ! autoaudiosink \
     uridecodebin3 uri=file:///$HOME/a.mp3 caps='audio/x-raw' \
     ! audioconvert ! \
     scaletempo ! audioconvert ! audioresample ! mix.

The audiomixer is there as I am working on implementing a cross-fade for my application.
When I try to change the rate of playback, I get the following error:

(bdj4player:33269): GStreamer-Audio-CRITICAL **: 
10:32:21.084: gst_audio_buffer_clip: 
assertion 'segment->format == GST_FORMAT_TIME || 
segment->format == GST_FORMAT_DEFAULT' failed

In the future there could be two streams with different rates of playback for each.

I can create debug output, but I don’t know what to look for. What can I do to fix this issue?