# WorkspaceBuilderError.callback(_:)

- **Package:** TmuxWorkspace
- **Language:** Swift
- **Kind:** constant
- **Source:** https://github.com/libtmux/libtmux-swift/blob/7993e7044347629b08020e9b02ae8bcffa0e5898/Sources/TmuxWorkspace/WorkspaceBuilder.swift#L385
- **Page:** https://libtmux.org/en/swift/latest/workspace/reference/workspacebuildererror-callback(_-)/

Whatever a configuration or event callback raised, carried whole: the caller that supplied the callback is the only one that can read it.