Using mapfile on the output of another command [duplicate]

Question

I want to edit a file before feeding it into an array. The data file contains:

Line 1
Line 2
Line 3

If I read it with

mapfile -t direct < data

I obtain a 3-element direct array

But I pipe the output of a sed command the edited array is empty:

sed s:Line:LINE: data | mapfile -t edited

As far as I can tell the sed output is fine (lines with LF separators) and replacing sed with a cat command doesn't improve things anyway.

What am I missing?

Answer 1

OK, thanks to @steeldriver, I saw the error in my ways. The mapfile must not be in a subshell, so this can be rewritten as:

 mapfile -t edited < <(sed s:Line:LINE: data)

and edited gets the expected contents.