Can't use "repeat=watch"

[Uatschitchun]

Am using the Ubuntu-version for Xenial (2.48.3), which is compiled with NATIVE=true.

When trying to run unison Own -repeat watch, I get: Fatal error: Server: No file monitoring helper program found

As the binary is compiled with NATIVE=true, there's no unison-fsmonitor binary. Getting the source and compiling with NATIVE=false, copying unison & unison-fsmonitor to /usr/local/bin, yields the same error!?

How do I get to have a repeat=watch?

Thx in advance

[DavidOliver]

I compiled Unison version 2.51.2 (OCaml 4.07.1) with NATIVE=true yesterday, and the unison-fsmonitor binary was created.

[jaewooklee93]

I got the same error message

Fatal error: No file monitoring helper program found

I installed unison with sudo apt install unison at Ubuntu 16.04 LTS, and it seemed that there's no unison-fsmonitor binary at the same directory as unison binary file is.

Is there any workaround for it? Should I build it from source code?

[vakker]

I'm having the same problem on Ubuntu 18.04 with sudo apt install unison.

[prokher]

I have the same issue in my Ubuntu-based Docker containers. My workaround is to install Unison manually:

# Manually install Unison (to sync folders) from sources cause Unison in
# the APT repository does not contain 'unison-fsmonitor'.
ARG UNISON_VERSION=2.51.2
RUN echo "Install Unison." \
    && pushd /tmp \
    && wget https://github.com/bcpierce00/unison/archive/v$UNISON_VERSION.tar.gz \
    && tar -xzvf v$UNISON_VERSION.tar.gz \
    && rm v$UNISON_VERSION.tar.gz \
    && pushd unison-$UNISON_VERSION \
    && make \
    && cp -t /usr/local/bin ./src/unison ./src/unison-fsmonitor \
    && popd \
    && rm -rf unison-$UNISON_VERSION \
    && popd

[jclaveau]

There is a bug on Launchpad tracking it: https://bugs.launchpad.net/ubuntu/+source/unison/+bug/1558737

[crockeea]

To follow up on the answer from @prokher, I had to install ocaml-native-compilers (Ubuntu) before make would succeed.

[gdt]

Seems like an Ubuntu issue, not a unison issue.