docker-syncが起動しない

Question

docker-syncを使用して、ホスト側であるMAC内のプロジェクトを、test_syncという同期用コンテナへコピーし、test_syncからwebサーバコンテナへマウントしようと試みているのですが、$ docker-sync startを実行すると、下記の様なメッセージが出て立ち上がりません。

    ok  Starting native_osx for sync test_sync
test_sync
/Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/lib/docker-sync/sync_strategy/native_osx.rb:97:in `start_container': Start failed (RuntimeError)
	from /Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/lib/docker-sync/sync_process.rb:105:in `start_container'
	from /Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/lib/docker-sync/sync_manager.rb:99:in `block in start_container'
	from /Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/lib/docker-sync/sync_manager.rb:98:in `each'
	from /Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/lib/docker-sync/sync_manager.rb:98:in `start_container'
	from /Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/tasks/sync/sync.thor:163:in `daemonize'
	from /Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/tasks/sync/sync.thor:47:in `start'
	from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/command.rb:27:in `run'
	from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in `invoke_command'
	from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor.rb:387:in `dispatch'
	from /Library/Ruby/Gems/2.3.0/gems/thor-0.20.0/lib/thor/base.rb:466:in `start'
	from /Library/Ruby/Gems/2.3.0/gems/docker-sync-0.5.2/bin/docker-sync:14:in `<top (required)>'
	from /usr/local/bin/docker-sync:22:in `load'
	from /usr/local/bin/docker-sync:22:in `<main>'

同期ストラテジはnative_osxですが、Home Brewにてfswatch unison rsyncなどもインストール・アップグレード成功しており、rsync, unisonなど他のストラテジも試しているのですが、ほぼ同様の結果となってしまいます。
お判りの方がおられたら、ぜひ御教示お願い致します。

環境
OS: MacOS 10.14.1 Mojave

$ docker -v
Docker version 18.05.0-ce-rc1, build 33f00ce

$ docker-compose -v
docker-compose version 1.21.0, build 5920eb0

$ docker-sync -v
0.5.2

---

以下は使用ファイルとなります。

docker-compose.yml

version: '2'

services
    test_db:
        container_name: test_db
        image: mysql:5.7.11
        ports:
            - "3306:3306"
        volumes:
            - ./db/mysql:/var/lib/mysql:cached
        environment:
            MYSQL_ROOT_PASSWORD: root
            MYSQL_DATABASE: defaultdb
            MYSQL_USER: defaultdbuser
            MYSQL_PASSWORD: defaultdbpasswd

    test_web:
        container_name: test_web
        environment:
            LANG: ja_JP.UTF-8
            TZ: Asia/Tokyo
        build: ./web
        ports:
            - "8000:80"
        volumes:
            - ../:/var/www/html:cached
        links:
            - test_db:db

    test_pma:
        container_name: test_pma
        image: phpmyadmin/phpmyadmin:4.5.3.1-1
        ports:
            - "8080:8080"
        links:
            - test_db:db

---

docker-compose.override.yml

version: '2'

volumes:
    test_sync:
        external: true

services:
    test_web:
        volumes:
            - test_sync:/var/www:nocopy
#            - test_sync:/var/www:rw
#            - ../../test:/var/www/test:cached

---

docker-sync.yml

version: '2'

options:
     unison_image: 'eugenmayer/unison:2.51.2.1'

syncs:
    test_sync:
        src: '../../test'
        sync_strategy: native_osx
#        sync_strategy: unison
#        sync_strategy: rsync
        sync_host_port: 10871
        sync_userid: 1000
#        sync_excludes: ['.git', 'gitignore', '.idea']
#        sync_args: "-copyonconflict -debug verbose"

---

FROM centos:centos7.3.1611

# TimeZone設定
RUN echo 'ZONE"=Asia/Tokyo"' > /etc/sysconfig/clock

# yumアップデート, 各種インストール
RUN yum -y update
RUN yum -y install yum-plugin-priorities
RUN yum -y install wget
RUN yum -y install git
RUN yum -y install unzip
RUN yum -y install net-tools
RUN yum -y groupinstall "Base" "Development tools" "Japanese Support"

# httpdをインストール
RUN yum install -y httpd
RUN rm -rf /etc/httpd/conf.d/welcome.conf

# httpd.conf編集
RUN sed -i "s/#ServerName www.example.com:80/ServerName localhost:80/g" /etc/httpd/conf/httpd.conf
RUN sed -i -e '/<Directory "/var/www/html">/,/</Directory>/s/    AllowOverride None/    AllowOverride All/' /etc/httpd/conf/httpd.conf
RUN sed -i -e 's/#EnableSendfile off/EnableSendfile off/' /etc/httpd/conf/httpd.conf
RUN sed -i -e 's/DocumentRoot "/var/www/html"/DocumentRoot "/var/www/test/public"/' /etc/httpd/conf/httpd.conf

# リポジトリ追加
RUN yum -y install epel-release
RUN rpm -ivh http://rpms.famillecollet.com/enterprise/remi-release-7.rpm
# RUN yum -y install http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm
RUN yum-config-manager --enable remi-php71

# PHP7, phpMyAdmin, 拡張パッケージ
RUN yum --enablerepo=remi-php71 -y install php php-mbstring php-pear php-opcache php-fpm php-pdo php-intl php-gd php-devel php-pecl-xdebug php-phpunit-PHPUnit php-mysql phpMyAdmin php-mcrypt

# php.ini編集
RUN sed -i -e 's/;date.timezone =/date.timezone = Asia/Tokyo/' /etc/php.ini
RUN sed -i -e 's/display_errors = Off/display_errors = On/' /etc/php.ini
RUN sed -i -e 's/post_max_size = 8M/post_max_size = 100M/' /etc/php.ini
RUN sed -i -e 's/upload_max_filesize = 2M/upload_max_filesize = 100M/' /etc/php.ini
RUN sed -i -e 's/;mbstring.language = Japanese/mbstring.language = Japanese/' /etc/php.ini
RUN sed -i -e 's/;mbstring.internal_encoding = EUC-JP/mbstring.internal_encoding = UTF-8/' /etc/php.ini
RUN sed -i -e 's/;mbstring.http_input = auto/mbstring.http_input = pass/' /etc/php.ini
RUN sed -i -e 's/;mbstring.http_output = SJIS/mbstring.http_output = pass/' /etc/php.ini
RUN sed -i -e 's/;mbstring.encoding_translation = Off/mbstring.encoding_translation = Off/' /etc/php.ini

# RUN sed -i -e 's/pdo_mysql.default_socket=/pdo_mysql.default_socket= /tmp/mysql.sock/' /etc/php.ini
# RUN sed -i -e 's/mysql.default_socket =/mysql.default_socket = /tmp/mysql.sock/' /etc/php.ini
# RUN sed -i -e 's/mysqli.default_socket =/mysqli.default_socket = /tmp/mysql.sock/' /etc/php.ini

RUN sed -i -e 's/pdo_mysql.default_socket=/pdo_mysql.default_socket = /var/lib/mysql/mysql.sock/' /etc/php.ini
RUN sed -i -e 's/mysql.default_socket =/mysql.default_socket = /var/lib/mysql/mysql.sock/' /etc/php.ini
RUN sed -i -e 's/mysqli.default_socket =/mysqli.default_socket = /var/lib/mysql/mysql.sock/' /etc/php.ini

# グループ編集
RUN groupmod -g 1000 apache
RUN usermod -u 1000 apache

# Composer
RUN curl -sS https://getcomposer.org/installer | php
RUN mv composer.phar /usr/local/bin/composer

# npm, nodejs
RUN yum -y install npm nodejs

# gulp
RUN npm install gulp -g

# bower
# RUN npm install bower -g

# xdebugの設定を追加
RUN printf "xdebug.max_nesting_level = 1000\n\
xdebug.var_display_max_depth = 3\n" >> /etc/php.d/xdebug.ini

EXPOSE 80

ENTRYPOINT ["/usr/sbin/apachectl"]

WORKDIR /var/www/test

CMD ["-DFOREGROUND"]