Cowbuilder

Cowbuilder
	Debian Package Building

To create the chroot to build your package in, PBuilder extracts a tarball. Especially for smaller packages, significant speedup can be gained if we do not copy all those files out of the tarball every time the package is built, but ise some copy-on-write construction instead.

Cowbuilder does just that.

Procedure 3. Prepare for using cowbuilder

Install the package

apt-get install cowbuilder

Edit ~/.pbuiderrc to suit cowbuilder

Near the top op ~/.pbuilderrc, put:

PDEBUILD_PBUILDER=cowbuilder
<snip>

Further down, add a line about BASEPATH:

<snip>
BASETGZ="/var/cache/pbuilder/$NAME-base.tgz"
# Cowbuilder understands no BASETGZ, but uses BASEPATH
BASEPATH=/var/cache/pbuilder/$NAME-base.cow
<snip>

and under "# Debian Configuration" add:

DEBOOTSTRAPOPTS=(${DEBOOTSTRAPOPTS[@]/--keyring=*})
DEBOOTSTRAPOPTS=(${DEBOOTSTRAPOPTS[@]} --keyring=/usr/share/keyrings/debian-archive-keyring.gpg)

Remove the old pbuilder chroots

sudo rm -rf /var/cache/pbuilder/*
Create new chroots

sudo DIST=precise cowbuilder --create --components "main universe multiverse" apprentice@host:~/packaging/hello-2.8$ sudo DIST=wheezy cowbuilder --create
Use PBuilder with COWBuilder

apprentice@host:~/packaging/hello-2.8$ DIST=trusty pdebuild apprentice@host:~/packaging/hello-2.8$ DIST=wheezy pdebuild
Separate places for separate distros' packages
If you amend the BUILDRESULT line in ~/.pbuilderrc a bit, like this:
```
BUILDRESULT="/var/cache/pbuilder/$NAME/result/"
if ! echo $@|grep -qe --create ; then
    BUILDRESULT=../build-area
    [ -n "${DIST}" ] && BUILDRESULT="${BUILDRESULT}/${DIST}"
#    [ -n "${ARCH}" ] && BUILDRESULT="${BUILDRESULT}/${ARCH}"
    install -d "${BUILDRESULT}"
    export BUILDRESULT="${BUILDRESULT}"
fi
	  
```
then after running
apprentice@host:~/packaging/hello-2.8$ DIST=wheezy pdebuild
you get:
apprentice@host:~/packaging/hello-2.8$ ls -trl ../build-area/wheezy/amd64 total 784 -rw-rw-r-- 1 apprentice apprentice 697483 mei 28 2012 hello_2.8.orig.tar.gz -rw-rw-r-- 1 apprentice apprentice 12602 jun 29 21:25 hello_2.8-4.debian.tar.gz -rw-r--r-- 1 apprentice apprentice 68654 jun 29 21:25 hello_2.8-4_amd64.deb -rw-rw-r-- 1 apprentice apprentice 1617 jun 29 21:25 hello_2.8-4.dsc -rw-rw-r-- 1 apprentice apprentice 2165 jun 29 21:25 hello_2.8-4_amd64.changes


pdebuild		Git-Buildpackage