.orElse(systemProperty(propertyName))
    .orElse(environmentVariable(propertyName))


val Project.buildBranch: Provider<String>
    get() = environmentVariable(BUILD_BRANCH).orElse(currentGitBranchViaFileSystemQuery())


/**
 * The logical branch.
 * For non-merge-queue branches this is the same as {@link #buildBranch}.
 * For merge-queue branches, this is the base branch.
 *

fun Project.releasedVersionsFile() = repoRoot().file("released-versions.json")


/**
 * We use command line Git instead of JGit, because JGit's `Repository.resolve` does not work with worktrees.
 */
fun Project.currentGitBranchViaFileSystemQuery(): Provider<String> = getBuildEnvironmentExtensionOrNull()?.gitBranch ?: objects.property(String::class.java)