Hello Raphael,
The work in libewf salsa repository was interrupted by upstream maintainer Joachim Metz.
He was against publishing libewf-experimental-20171104 [1] into debian unstable and insisted on using legacy version libewf-20140807 [2].
Salsa watch file points to the wrong repository, the version 20140807 is last stable version, and the version 20171104 from experimental should not migrate.
I and Hilko did not had time to correct wrong and half-done salsa git history. I believe we should
1. Rename current debian/master branch to debian/master-old (or something)
2. Start new debian/master from the commit it diverged with published version and use gbp import-orig/import-dsc
3. Do the same for the debian/expiremental branch
Some time ago I've partly done this work in [3], but now I'm overloaded with another project.