A tool to relaunch jbuilder build when a file modification is detected via fswatch or inotifywait.

Requirements

Of course, we need jbuilder (or dune). In addition, the following file system monitor command is required:

• Mac OS X: fswatch

• Linux: inotifywait

In Linux, there is a limit of number of file monitorings per user,
and inotifywait command fails if there are too many files under
the directory of dune_watch is running. The issue may be solved
by increasing the limit may solve the issue:
https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers

Limitation

Currently it only tested with Mac OS X with fswatch and Linux with inotifywait.

How to use

At the top of your project,

$ dune_watch

then it executes jbuilder build --dev build command.
Once the command finishes, dune_watch monitors file modification
under the directory where it is launched and relaunches the build command
when necessary.