This page describes some basics in taking a package from https://invent.kde.org/neon/ and building it locally. This can be useful for doing local testing before committing changes.

Prerequisites

A pre-existing KDE development environment.
dpkg-dev and xbuilder packages will include the standard Debian toolchain for building packages.

Setting up local files for building package

Clone the package repository repository, i.e. https://invent.kde.org/neon/kde/libkdegames
Copy the source tree from your kde sources to where the debian/ path resides.
Create a usr/share/locale to simulate CI locale injection, mkdir -p usr/share/locale && touch usr/share/locale/stub
Remove symbols to simulate CI removing the symbol files, rm debian/*.symbols
Change debian/source/format to use native instead of quilt, sed -i 's/quilt/native/' debian/source/format
Apply patches, QUILT_PATCHES=debian/patches quilt push -a

Or, in one command:

mkdir -p usr/share/locale && touch usr/share/locale/stub && rm -f debian/*.symbols && sed -i 's/quilt/native/' debian/source/format && QUILT_PATCHES=debian/patches quilt push -a

Building the package

Use your favorite tool:

dpkg-buildpackage
debuild

Known false negatives

Complaints about dsc and missing key.
Lintian returns malformed-debian-changelog-version.

Speeding up compilation

A compiler cache can help speed things up immensely, particularly when it comes to packages that take a while to compile.

Install ccache. It might be worth also setting these options:

ccache -o max_size="20G" - Increases the cache size to 20G, roughly kdesrc-build uses about 12G currently and the default is 10G.
ccache -o compression="true" - Enable compression, reduces cache size by compressing objects.
ccache -o compression_level="9" - Highest level of compression, helps utilize your space significantly better at a relatively minimal performance cost.

Configure ~/.devscripts to use ccache when using debuild:

echo 'DEBUILD_PREPEND_PATH="/usr/lib/ccache"' | tee -a ~/.devscripts

Now you should be able to use debuild with ccache. You may want to validate this by checking its' usage statistics while building, use ccache -s.