I have modified a source file in the i915 source code.
I have just edited the file and made a change to one line.
I have not made a patch file because I couldn't work out how to do that.
When I build with
make -j `getconf _NPROCESSORS_ONLN` deb-pkg LOCALVERSION=-custom
or with
make -j `getconf _NPROCESSORS_ONLN` deb-pkg LOCALVERSION=-custom -i
I get
update-version-dkms
dpkg-source: info: use the '3.0 (quilt)' format to have separate and documented changes to upstream files, see dpkg-source(1)
dpkg-source: error: unrepresentable changes to source
dpkg-buildpackage: error: dpkg-source -i.git -b ubuntu-bionic subprocess returned exit status 1
scripts/package/Makefile:71: recipe for target 'deb-pkg' failed
make[1]: [deb-pkg] Error 1 (ignored)
Then I committed that change tp a new branch and checked out a standard tag (a standard upstream version). Previously it built. Now it doesn't, same error.
the answer here hints at some bad files (example vim swap files) but I can't work out what the problems may be: "dpkg-source: unrepresentable changes to source" when trying to debuild a modified package
does not help me.
Best Answer
Ah, my local changes were a red-herring. somehow a python script got added in part of the source tree, some kind of debugging assistant.
To fix: 1 Following instructions here to remove all non-tracked files from the working tree
https://koukia.ca/how-to-remove-local-untracked-files-from-the-current-git-branch- 571c6ce9b6b1
I did
at step 4, copy the config in.
Then it builds.
these are my complete notes. Some of these steps are unnecessary but they don't hurt. Obviously, ignore the cherry-pick.