file-trailing-single-newline shows error after fixing files

[jackbentley]

Running file-trailing-single-newline results in the following error. However, the files are fixed correctly. Rerunning it doesn't pick anything up and returns successfully.

$ file-trailing-single-newline --fix --path=./

$ find ./ -type f    -print0 | xargs -0 -P 8 -n1  sh -c 'if [ -f "${1}" ]; then aci-trailing-newline -1 "$1" || ((echo "" >> "$1" && sed -i "" -e :a -e "/^\n*\$/{\$d;N;ba" -e "}" "$1") && echo "Fixing: $1" || echo "FAILED: $1"); fi' --
Fixing: ./file.conf
[ERR] Some files do not have exactly one trailing newline.