@romildo, thanks for your PR! By analyzing the history of the files in this pull request, we identified @oxij, @MarcWeber and @maggesi to be potential reviewers.

@romildo this failed on darwin due to unicode normalization. I pushed a commit that should fix the hash problem, let's see what travis says...

On Darwin

In file included from act_dedupefiles.c:4:

./jdupes.h:23:10: fatal error: 'linux/btrfs.h' file not found

#include <linux/btrfs.h>

         ^~~~~~~~~~~~~~~

1 error generated.

Should there not be an alias with a deprecation warning?

How significant is this package? Using an alias can offer a smoother transition but how many people use this package and is it worth going through that extra effort (how little it is)

@romildo can you make this PR only about jdupes: init at 1.8 ?

fdupes should not be deprecated yet. Its former home on Google Code has moved to a GH repo and there has been new dev since.
People might be using it in shell scripts and such and the two tools are not interchangeable (different options). So let's keep both in nixpkgs. :)

can you make this PR only about jdupes: init at 1.8 ?

@c0bw3b Done.

Thanks! You missed @bennofs workaround to avoid src hash being different on Darwin (testdir subdirectories contains unicode characters in their names) :

  src = fetchFromGitHub {
    owner = "jbruchon";
    repo  = "jdupes";
    rev   = "v${version}";
    sha256 = "0nswqylzgpgqgcfgl99dkrcs05zxpzj5dcla2ib9mywl4xavszax";
    postFetch = "$unpackCmd $downloadedFile && rm -r ${name}/testdir";
  };

Also BTRFS support should be enabled on Linux platforms only :

  makeFlags = [ "PREFIX=$(out)" ] ++ stdenv.lib.optional stdenv.isLinux "ENABLE_BTRFS=1";

You missed @bennofs workaround to avoid src hash being different on Darwin.

Also BTRFS support should be enable on Linux platforms only.

Sorry. Fixed now.

@bennofs The attribute

postFetch = "$unpackCmd $downloadedFile && rm -r ${name}/testdir";

in src is not working. It is giving the following error:

 /nix/store/bl48w7h24n6379fa200yv60n4pwynd9c-stdenv/setup: line 69: /tmp/nix-build-jdupes-v1.8-src.drv-14/file: Permission denied

It seems that $unpackCmd is expanding to the empty string. What I am missing here?

I think removing the testdir directory now works with the following:

  src = fetchFromGitHub {
    owner = "jbruchon";
    repo  = "jdupes";
    rev   = "v${version}";
    sha256 = "17cgh3j6z4rl8ay06s8387a2c49awfv1w3b2a11z4hidwry37aiq";
    # Unicode file names lead to different checksums on HFS+ vs. other
    # filesystems because of unicode normalisation. The testdir
    # directories have such files and will be removed.
    extraPostFetch = "rm -r $out/testdir";
  };

Ah yes you are right it is much nicer this way.
I'm pretty sure the previous patch I struggled to find again was doing just that. :)