classicpress_dev_version_info()

function classicpress_dev_version_info() {
	if ( ! classicpress_is_dev_install() ) {
		return;
	}

	$git_head = ABSPATH . '../.git/HEAD';
	$git_commit = null;
	if ( @is_file( $git_head ) ) {
		$git_head = trim( file_get_contents( $git_head ) );
		if ( preg_match( '#^ref: (refs/.*)$#', $git_head, $matches ) ) {
			// on a branch
			$git_head = ABSPATH . '../.git/' . $matches[1];
			if ( @is_file( $git_head ) ) {
				$git_commit = trim( file_get_contents( $git_head ) );
			}
		} else {
			// detached HEAD
			$git_commit = $git_head;
		}
	}

	if ( ! $git_commit ) {
		return;
	}

	echo '<span class="dev-version-info">';
	/* translators: current development commit on GitHub */
	printf(
		__( 'commit %s' ),
		substr( $git_commit, 0, 8 )
	);
	echo '</a>';
	echo '</span>';
}