Function build_with_git 

pub fn build_with_git(
    input: &BuildInput<'_>,
) -> Result<GitBuilt, TransactionStop>

What: Runs real git commit against the scratch repository and reads the commit it made. Why: Git’s own output, editor and signer reach the person’s terminal as they would from a plain git commit; a nonzero status of Git is the command’s status and nothing lands.

In TS you’d write (pseudocode):

await buildWithGit(input)

Errors

TransactionStop::NativeExit with Git’s status when Git declined or was aborted (an empty message, an editor that failed, a signer that failed); TransactionStop::Message when Git could not be started.