Few of the possible issues are discussed over here:
1. Problem: "Failed to upload artifacts: Invalid arn" When Running a Build
When you run a build, the UPLOAD_ARTIFACTS build phase fails with the error Failed to upload artifacts: Invalid arn.
Possibilities: Your Amazon S3 output bucket is in a different AWS region than the AWS CodeBuild build project.
Solutions: You can edit the project and point the proper s3 bucket which is in your region.
2. Problem: Runtime error (did not find expected alphabetic or numeric character at line XX)
After the provisioning phase of build, when the DOWNLOAD_SOURCE phase is encountered, it will try to check the BuildSpec.yml and fail at that moment.
Possibilities: The syntax and expected output of the BuildSpec.yml parameter will not be correct.
Solutions: You can edit the BuildSpec.yml properly and mention...