Debian packaging of LinuxCNC
============================

The following steps were performed to transform Upstream's git repository
into
 - a source tarball and
 - a debian subdirectory
for Debian's main distribution.

LinuxCNC is used across a wide span of releases, now supporting from
Squeeze up to the latest version of Ubuntu. Not too many changes are
required for Debian unstable.

Steps
-----

1. Generate the source tarball, This will use the version as specified
   in the first line of the debian/changelog file. And maybe remove
   anything outdated, just to avoid confusions:

   If this is not the original tarball but an interim git tag/snapshot,
   then set the version in debian/changelog. For git checkout, the
   version stated in debian/changelog receives the suffix +gitYYYYMMDD.githash

   VERSION=$(head -n1 debian/changelog |cut -f2 -d' ' | tr -d "()" | sed -e 's/^[0-9]://' )

   If the current source tree is not the regular release but git checkout also
   create the fitting tarball:

   VERSION=$(git log --date=format:%Y%m%d --pretty=${VERSION}+git%cd.%h| head -n1)
   echo $VERSION
   foldername=$(basename $(pwd))
   (cd .. && tar --exclude=.git -cJvf "linuxcnc_${VERSION}.orig.tar.xz" "$foldername")
   du -sh ../$foldername

2. Prepare shell to work in temp directory

   export VERSION
   export WORKDIR=$(mktemp -d)
   mv "../linuxcnc_${VERSION}.orig.tar.xz" ${WORKDIR}/ && \
   pushd $WORKDIR && bash
   echo -n "I: Now working in "; pwd

3. Unpack

   tar xJvf linuxcnc_*.orig.tar.xz
   cd linuxcnc


4. Configure debian directory for the "uspace" packages that are
   prepared for the Non-RTAI but preempt realtime kernels that are
   distributed with Debian.

   debian/configure

5. Slightly adapt for upload to d/unstable

   sed -i '1s/ UNRELEASED;/ unstable;/' debian/changelog

   mkdir -p debian/source
   echo "3.0 (quilt)" > debian/source/format

   # debian version
   sed -i "1s/^.*;/linuxcnc ($VERSION-1) unstable;/" debian/changelog

6a. build Debian package if in doubt - optional

   dpkg-buildpackage

6b. build Debian source package, which is what is uploaded to Debian upon acceptance and for updates

   dpkg-buildpackage -S

7. test build in cowbuilder

   sudo cowbuilder --update
   sudo cowbuilder --build ../linuxcnc_*.dsc

8. check that nothing avoidable slipped through

   lintian -i /var/cache/pbuilder/results/linuxcnc_*.changes

8. get all the files just created

   exit
   mv ${WORKDIR}/linuxcnc_* ..

Above sketched differences are not impeding routine workflows of Debian
packaging. For instance we found that the routine-update script (from the
Debian Science team) deals with these adaptations just fine.


How to contribute
-----------------

LinuxCNC does not have a representation on salsa.debian.org. 
Please join us on https://github.com/LinuxCNC/linuxcnc/ .