无法将构建工件复制到 S3 存储桶

我试图使用 cp 命令将代码构建期间生成的文件复制到 S3 存储桶。我可以看到该文件，但是当我尝试复制该文件时，它说文件不存在。我仍然很困惑为什么我不能复制文件。请检查下面的 Buildspec.yml。

version: 0.2 
phases: 
  install: 
    commands: 
      - echo Installing MySQL 
      - apt update 
      - apt-get install mysql-client -y 
      - mysqldump --version
      - mysqldump -h ***** -u $User -p****--no-data --routines --triggers -f testdb > ./backup.sql 
      - ls
      - aws s3 cp backup.sql s3://dev-test --recursive --acl public-read --cache-control "max-age=100"
  post_build: 
    commands: 
      - echo Build completed on `date` 

请检查 AWS Codebuild 生成的日志。

Logs:

[Container] 2021/04/26 02:55:41 Running command mysqldump -h ***** -u $User -p****--no-data --routines --triggers -f testdb > ./backup.sql

[Container] 2021/04/26 02:55:43 Running command ls
Jenkinsfile
README.md
backup.sql
buildspec.yml
utils.groovy

[Container] 2021/04/26 02:55:43 Running command aws s3 cp backup.sql s3://dev-test --recursive --acl public-read --cache-control "max-age=100"
warning: Skipping file /codebuild/output/src985236234/src/backup.sql/. File does not exist.
Completed 0 file(s) with ~0 file(s) remaining (calculating...)

[Container] 2021/04/26 02:55:44 Command did not exit successfully aws s3 cp backup.sql s3://dev-test --recursive --acl public-read --cache-control "max-age=100" exit status 2
[Container] 2021/04/26 02:55:44 Phase complete: INSTALL State: FAILED
[Container] 2021/04/26 02:55:44 Phase context status code: COMMAND_EXECUTION_ERROR Message:   Error while executing command: aws s3 cp backup.sql s3://dev-test --recursive --acl public-read --cache-control "max-age=100". Reason: exit status 2```