Issue building CKEditor

I am on Ubuntu 14.04 and I would like to create a build of CKEditor. I've read:  http://docs.ckeditor.com/#!/guide/dev_build

First issue: I don't have any "build.sh" in my CKEditor folder. Solution: download https://github.com/ckeditor/ckeditor-dev/blob/master/dev/builder/build.sh

Second issue: the build.sh above is not totaly correct, I had to modify some locations (e.g. "../.." instead of "."). But I think it's now ok since I don't have messages like "file not found" anymore...

Third issue: I've several warnings like:

 WARNING: it was impossible to update the lang property in /home/sebsheep/progs_div/albums_tests/ckeditor/release/ckeditor/plugins/youtube/plugin.js

Moreover, I've the impression that CKBuilder only copy my initial folder recursively, as we can see with "/ckeditor/release/ckeditor/release/ckeditor/release/ckeditor/release/ckeditor/release/ckeditor" (thoses files actually are on my disc) on this message: 

WARNING: it was impossible to update the lang property in /home/sebsheep/progs_div/albums_tests/ckeditor/release/ckeditor/release/ckeditor/release/ckeditor/release/ckeditor/release/ckeditor/plugins/indent/plugin.js

Those warnings never stop, I have to C-c in order to stop the program.

What am I doing wrong?

PS : make the links functionnal trigger the spam filter... It's quite annoying...