--8<---------------cut here---------------start------------->8---
# generate a big file
dd bs=1M count=4096 if=/dev/zero of=/tmp/chungus
# serve it
guix shell woof -- woof -i 127.0.0.1 -p 1111 -c 1 /tmp/chungus
# build the source derivation
guix build --no-grafts -Sf bug.scm
# observe the error
# guix build: error: short write in copy_file_range `15' to `16': No such file or directory
--8<---------------cut here---------------end--------------->8---

-- 
Ricardo