unison doesn't include unison-fsmonitor for macOS, thus -repeat watch option doesn't work out of the box. This utility fills the gap. This implementation was originally made for macOS but shall work on other platforms as well like Linux, Windows.

brew install autozimu/homebrew-formulas/unison-fsmonitor

Alternatively if you have cargo installed,

cargo install unison-fsmonitor

Simply run unison with -repeat watch as argument or repeat=watch in config file.

You might need to update file watch limits in both hosts if watching limit reached. See https://facebook.github.io/watchman/docs/install#system-specific-preparation for more details.

RUST_LOG=debug unison

• Protocol https://github.com/bcpierce00/unison/blob/af8669bb26f88e85bdc37cb1ff23d9bb0685a1e2/src/fswatch.ml
• https://github.com/bcpierce00/unison/blob/master/src/fsmonitor/watchercommon.ml
• https://github.com/hnsl/unox