println!() a lot.
But that panics when piping, for example:
$ imag store ids | head -n 1
thread 'main' panicked at 'failed printing to stdout: Broken pipe (os error 32)', src/libstd/io/stdio.rs:692:8
note: Run with `RUST_BACKTRACE=1` for a backtrace.
imag-store exited with non-zero exit code
Thus, we should rewrite the appropriate parts to use
write!() and handle errors properly.