[Unison-hackers] Unison on a Synology DS412+

[Benjamin C. Pierce]

> A short digression before the real subject: a huge thanks to all the
> unison developers for probably the most reliable software I've being using.

Glad you're finding it useful!  :-)

> Unfortunately, inotify-compat.h is not included in the svn repository.
> I've found a similar file in the ocaml-inotify repository
> https://github.com/vincenthz/ocaml-inotify, but for some reason, it does
> not compile on the DS412+. Probably a too old version of something. I
> was however successful with a comparable header from inotify-tools,
> here:
> https://github.com/rvoicilas/inotify-tools/blob/master/libinotifytools/src/inotifytools/inotify-nosys.h.
> So I would recommend to add to the svn repository something similar to
> this old glibc workaround.

I don't have it on my system either.  If it's working for you, perhaps we should add the version you used to the repo, if it's license-compatible.

> 3) selftest
> A final note: while the obtained binary seems to work, selftest does
> not. More precisely, I've got:
> nas> ./unison -selftest
> Contacting server...
> Running internal tests...
> fastercheckUNSAFE 1...
> Test fastercheckUNSAFE 1 / 3b:
> Expected R2 =
>  Dir [("x", File "f00")]
> but found
>  Dir [("x", File "bar")]
> 
> Fatal error: Self-test fastercheckUNSAFE 1 / 3b failed!
> 
> Disturbingly, I've got the very same error on a standard ubuntu 12.04
> box (here this is with ocaml 3.12.1). I'm probably doing something wrong.

On OSX (10.8), the -selftest goes through fine.  So there seems to be a difference in the way the fastercheckUNSAFE option is behaving on linux.  That is, indeed, worth investigating a bit.

If you'd like to experiment, have a look at the test that's being run, in the file test.ml.  Even without knowing OCaml, it should be fairly clear what's going on.  If you do the same sequence of file modifications and syncs manually, do you get the same incorrect result?

Best,

    - Benjamin