> Running this simple test using clock from sutils to produce a repeating one second interval input stream..

> 

> mkfifo fifo

> clock -i 1 -sf "T> stream one" >fifo &

> clock -i 1 -sf "D> stream two" >fifo &

> cat fifo

> 

> on void musl only the second fifo input stream is displayed.

> on void glibc, both input streams are displayed interleaved as expected.

> 

> Are fifo buffers handled differently under musl?

I looked up the sutils source and see it's flushing after each output,

and tried it on an Alpine-based box here (with musl) and could not

reproduce what you're seeing. Both outputs are visible and roughly

interleaved (although their order sometimes swaps with scheduling, of

course).