Prior to 1.7, jo would place an empty string as the field value rather than throwing an error.

touch empty_file
jo "value=@empty_file"

On 1.7:

jo: Error reading file empty_file

Prior to 1.7:

{"value":""}

Based on the changelog, I think this refactor was the cause of the new behavior: #192

--

I found this behavior because it broke a script that did something like the following:

local stdout="$(mktemp)"
local stderr="$(mktemp)"

brew install somepackage 1>"$stdout" 2>"$stderr"

jo stdout="@$stdout" stderr="@$stderr"

When there is nothing in stderr, the resulting file is empty, which now causes jo to throw an error.