secondarySourceVersions

An array of ProjectSourceVersion objects. Each ProjectSourceVersion must be one of:

For CodeCommit: the commit ID, branch, or Git tag to use.
For GitHub: the commit ID, pull request ID, branch name, or tag name that corresponds to the version of the source code you want to build. If a pull request ID is specified, it must use the format pr/pull-request-ID (for example, pr/25). If a branch name is specified, the branch's HEAD commit ID is used. If not specified, the default branch's HEAD commit ID is used.
For Bitbucket: the commit ID, branch name, or tag name that corresponds to the version of the source code you want to build. If a branch name is specified, the branch's HEAD commit ID is used. If not specified, the default branch's HEAD commit ID is used.
For Amazon S3: the version ID of the object that represents the build input ZIP file to use.