CircleCi - only build features that has changed

buildWhenAffected.sh

##################
### config.yml ###
##################

version: 2
jobs:
    build:
        docker:
            - image: circleci/python:3.6
        steps:
            - checkout
            - run:
                command: |
                    .circleci/commit_check.sh



#######################
### commit_check.sh ###
#######################

set -e

# latest commit
LATEST_COMMIT=$(git rev-parse HEAD)

# latest commit where path/to/folder1 was changed
FOLDER1_COMMIT=$(git log -1 --format=format:%H --full-diff path/to/folder1)

# latest commit where path/to/folder2 was changed
FOLDER2_COMMIT=$(git log -1 --format=format:%H --full-diff path/to/folder2)

if [ $FOLDER1_COMMIT = $LATEST_COMMIT ];
    then
        echo "files in folder1 has changed"
        .circleci/do_something.sh
elif [ $FOLDER2_COMMIT = $LATEST_COMMIT ];
    then
        echo "files in folder2 has changed"
        .circleci/do_something_else.sh
else
     echo "no folders of relevance has changed"
     exit 0;
fi

The circlci example at https://circleci.com/docs/2.0/configuration-cookbook/?section=examples-and-guides#execute-specific-workflows-or-steps-based-on-which-files-are-modified returns below error:

[#/jobs/check-updated-files] 0 subschemas matched instead of one
1. [#/jobs/check-updated-files] only 0 subschema matches out of 2
|   1. [#/jobs/check-updated-files] no subschema matched out of the total 2 subschemas
|   |   1. [#/jobs/check-updated-files] 0 subschemas matched instead of one
|   |   |   1. [#/jobs/check-updated-files] expected type: Mapping, found: Sequence
|   |   |   |   SCHEMA:
|   |   |   |     type: object
|   |   |   |   INPUT:
|   |   |   |     - filter:
|   |   |   |         mapping: |
|   |   |   |           service1/.* run-build-service-1-job true
|   |   |   |           service2/.* run-build-service-2-job true
|   |   |   |         base-revision: master
|   |   |   |         config-path: .circleci/config.yml

i get the same ^