bash has a bug with things like $'\001' in functions (in this case src_unpack() when those functions are stored as part of the env storing done by paludis. I've reported the bug upstream but pending resolution of that bug could you kindly as a workaround replace testExp=$'\nnn' with testExp=$(echo -e '\0nnn') to make it work for paludis users?
Created attachment 118107 [details, diff] like this
Fixed, thanks.