Comment 3 for bug 838720

Sylvain, this package is small so your diff shouldn't be a problem but when using diff directly its a good practice that all +++ lines, which are like metadata about where to apply the patch, contain the same name as the originals with a relative path 1 level higher than the package tree, specially when the diff patchesmore than one file.

So it gets like this:
--- iso-scan.orig/debian/iso-scan.postinst
+++ iso-scan/debian/iso-scan.postinst

And the dev, just needs to cd $PACKAGE; patch -p1 < patchfile instead of patch originalfile patchfile

I'm not sure why I had doubts in #1 but this bug does affect debian too and its just that line (I thought there were 2...).
I'll open a bug upstream.

Optionally, If you want, you can fix it directly by purposing a merge to the branch lp:~ubuntu-core-dev/iso-scan/ubuntu using the procedure mentioned in https://wiki.ubuntu.com/Bugs/HowToFix