diff --git a/.gitignore b/.gitignore
index b25bee0c..2d80b031 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,3 +23,7 @@ PySolFC-Cardsets--Minimal-2.0/
 PySolFC-Cardsets--Minimal-2.0.*
 PySolFC-Cardsets-2.0/
 PySolFC-Cardsets-2.0.*
+
+android/bin/keystore
+android/*.zip
+android/*.apk
diff --git a/MANIFEST.in b/MANIFEST.in
index f329b572..9cb0df19 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -20,7 +20,7 @@ graft data/themes
 recursive-exclude data/themes *.py
 include scripts/build.bat scripts/create_iss.py scripts/mahjongg_utils.py
 include scripts/all_games.py scripts/cardset_viewer.py
-include scripts/cardconv scripts/cardsetsgiftobmp
+include scripts/cardconv
 include scripts/gen_individual_importing_tests.py
 include tests/individually-importing/PLACEHOLDER
 recursive-include tests/lib *.pm *.py
diff --git a/README.android b/README.android
index fd55f229..756a3b51 100644
--- a/README.android
+++ b/README.android
@@ -70,7 +70,7 @@ Cardsets:
 
 Cardsets should be installed in ${HOME}/.PySolFC/cardsets/. On an
 android device this is equivalent to /sdcard/.PySolFC/cardsets/.
-Cardsets must use the bmp image format. Use scripts/cardsetsgiftobmp
+Cardsets must use the bmp image format. Use scripts/cardconv
 (on a linux system) to convert them, before copying to the device.
 
 Possible known build issues:
diff --git a/README.kivy b/README.kivy
index 2f97bbc6..21bf402f 100644
--- a/README.kivy
+++ b/README.kivy
@@ -39,7 +39,7 @@ kivy version.
 
 Additional cardsets are available from the SourceForge
 project. To use them with kivy, they need to be converted to
-the BMP format. A shell script, 'cardsetsgiftobmp' , has been added
+the BMP format. A shell script, 'cardconv' , has been added
 to the scripts directory (it requires Bash and ImageMagick).
 
 For all GIF images in the directories data/images and data/tiles ,
diff --git a/README.md b/README.md
index 053117e8..e607ca02 100644
--- a/README.md
+++ b/README.md
@@ -144,7 +144,6 @@ mkdir -p "$PKGDIR"
 
 ## Alternate toolkit.
 
-- Python2 (2.7 or later)
 - Kivy (10.0 or later)
 
 - Features:
@@ -154,7 +153,7 @@ mkdir -p "$PKGDIR"
 - Running from source without installation:
 
 ```
-python2 pysol.py --kivy
+python pysol.py --kivy
 ```
 
 ### Configuring Freecell Solver
diff --git a/android/debian/README b/android/debian/README
index 93bcdabc..e9db191d 100644
--- a/android/debian/README
+++ b/android/debian/README
@@ -10,9 +10,6 @@ root$ ./apt-install.sh
 
 root$ exit
 
-user$ ./pip-install.sh
-- .....some output.
-
 Now all required packages are installed to proceed with the
 android build.
 
diff --git a/android/debian/apt-installs.sh b/android/debian/apt-installs.sh
index 4b4f7ca9..6db7e2d2 100755
--- a/android/debian/apt-installs.sh
+++ b/android/debian/apt-installs.sh
@@ -1,12 +1,20 @@
-#!/bin/bash
-# als root ausführen!
+#!/bin/sh
+set -e
 
-apt-get install -y mercurial git default-jdk
-apt-get install -y cython cython3
-apt-get install -y python3-pip
-apt-get install -y python3-yaml
-apt-get install -y virtualenv
-apt-get install -y pkg-config
-apt-get install -y automake autoconf libtool
-apt-get install -y zlib1g-dev
-apt-get install -y libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev
+# install as root
+
+apt-get install -y \
+  git \
+  openjdk-8-jdk \
+  cython3 \
+  python3-pip \
+  python3-yaml \
+  virtualenv \
+  pkg-config \
+  automake autoconf libtool \
+  zlib1g-dev \
+  libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev \
+  libtinfo5 \
+  lld
+
+update-alternatives --set java /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java
diff --git a/android/debian/pip-installs.sh b/android/debian/pip-installs.sh
deleted file mode 100755
index 4e0ae212..00000000
--- a/android/debian/pip-installs.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-#!/bin/bash
-
-# als user installieren !
-
-python3 -m pip install --user pyasn1
-python3 -m pip install --user pyasn1_modules
-python3 -m pip install --user requests
-python3 -m pip install --user clint
diff --git a/android/initsdk b/android/initsdk
new file mode 100755
index 00000000..3639c3b7
--- /dev/null
+++ b/android/initsdk
@@ -0,0 +1,26 @@
+#!/bin/bash
+set -eux
+# This script mimics the instructions laid out in the p4a documentation:
+# https://python-for-android.readthedocs.io/en/latest/quickstart/
+
+. mkp4a.common
+
+if [[ -d $sdkdir && -d $ndkdir ]]; then
+  echo "Skipping SDK and NDK installation: SDK and NDK directories already exist."
+  exit
+fi
+
+urlbase=https://dl.google.com/android/repository/
+tools_zip=sdk-tools-linux-4333796.zip
+ndk_zip=android-ndk-r17c-linux-x86_64.zip
+
+mkdir -p $sdkdir $ndkdir
+
+[ -a $ndk_zip ] || wget $urlbase/$ndk_zip
+unzip -d $(dirname $ndkdir) $ndk_zip
+
+[ -a $tools_zip ] || wget $urlbase/$tools_zip
+unzip -d $sdkdir $tools_zip
+
+$sdkdir/tools/bin/sdkmanager 'platforms;android-27'
+$sdkdir/tools/bin/sdkmanager 'build-tools;29.0.1'
diff --git a/android/initsdk.py b/android/initsdk.py
deleted file mode 100755
index edc5267a..00000000
--- a/android/initsdk.py
+++ /dev/null
@@ -1,243 +0,0 @@
-#! /usr/bin/env python3
-# -*- coding: iso-8859-1 -*-
-
-import glob
-import hashlib
-import logging
-import os
-import sys
-from zipfile import ZipFile, ZipInfo
-
-from clint.textui import progress
-
-import requests
-
-
-cachefiles = [
-  ('https://dl.google.com/android/repository/platform-tools-latest-linux.zip',
-   '',
-   'platform-tools'),
-  ('https://dl.google.com/android/repository/tools_r25.2.5-linux.zip',
-   '577516819c8b5fae680f049d39014ff1ba4af870b687cab10595783e6f22d33e',
-   'tools'),
-  ('https://dl.google.com/android/repository/android-19_r04.zip',
-   '5efc3a3a682c1d49128daddb6716c433edf16e63349f32959b6207524ac04039',
-   'platform'),
-  ('https://dl.google.com/android/repository/build-tools_r26-linux.zip',
-   '7422682f92fb471d4aad4c053c9982a9a623377f9d5e4de7a73cd44ebf2f3c61',
-   'build-tools'),
-  ('https://dl.google.com/'
-   'android/repository/android-ndk-r12b-linux-x86_64.zip',
-   'eafae2d614e5475a3bcfd7c5f201db5b963cc1290ee3e8ae791ff0c66757781e',
-   'ndk'),
-]
-
-# https://stackoverflow.com/questions/39296101:
-
-
-class MyZipFile(ZipFile):
-
-    def extract(self, member, path=None, pwd=None):
-        if not isinstance(member, ZipInfo):
-            member = self.getinfo(member)
-
-        if path is None:
-            path = os.getcwd()
-
-        ret_val = self._extract_member(member, path, pwd)
-        attr = member.external_attr >> 16
-        os.chmod(ret_val, attr)
-        return ret_val
-
-# Reused from fdroidserver:
-
-
-def sha256_for_file(path):
-    with open(path, 'rb') as f:
-        s = hashlib.sha256()
-        while True:
-            data = f.read(4096)
-            if not data:
-                break
-            s.update(data)
-        return s.hexdigest()
-
-# Adapted from fdroidserver:
-
-
-def update_cache(cachedir, cachefiles):
-    for srcurl, shasum, typ in cachefiles:
-        filename = os.path.basename(srcurl)
-        local_filename = os.path.join(cachedir, filename)
-
-        if os.path.exists(local_filename):
-            local_length = os.path.getsize(local_filename)
-        else:
-
-            local_length = -1
-
-        if (typ == 'ndk') and (ndkloc is not None):
-            continue
-        elif (typ != 'tools') and (sdkloc is not None):
-            continue
-
-        resume_header = {}
-        download = True
-
-        try:
-            r = requests.head(srcurl, allow_redirects=True, timeout=60)
-            if r.status_code == 200:
-                content_length = int(r.headers.get('content-length'))
-            else:
-                content_length = local_length  # skip the download
-        except requests.exceptions.RequestException as e:
-            content_length = local_length  # skip the download
-            logger.warn('%s', e)
-
-        if local_length == content_length:
-            download = False
-        elif local_length > content_length:
-            logger.info('deleting corrupt file from cache: %s',
-                        local_filename)
-            os.remove(local_filename)
-            logger.info("Downloading %s to cache", filename)
-        elif local_length > -1 and local_length < content_length:
-            logger.info("Resuming download of %s", local_filename)
-            resume_header = {
-                'Range': 'bytes=%d-%d' % (local_length, content_length)}
-        else:
-            logger.info("Downloading %s to cache", filename)
-
-        if download:
-            r = requests.get(srcurl, headers=resume_header,
-                             stream=True, verify=False, allow_redirects=True)
-            content_length = int(r.headers.get('content-length'))
-            with open(local_filename, 'ab') as f:
-                for chunk in progress.bar(
-                        r.iter_content(chunk_size=65536),
-                        expected_size=(content_length / 65536) + 1):
-                    if chunk:  # filter out keep-alive new chunks
-                        f.write(chunk)
-        if not shasum == '':
-            v = sha256_for_file(local_filename)
-            if v == shasum:
-                logger.info("Shasum verified for %s", local_filename)
-            else:
-                logger.critical(
-                  "Invalid shasum of '%s' detected for %s", v, local_filename)
-                os.remove(local_filename)
-                sys.exit(1)
-
-# Build the sdk from zips.
-
-
-def build_sdk(sdkdir, cachedir, cachfiles):
-    for srcurl, shasum, typ in cachefiles:
-        filename = os.path.basename(srcurl)
-        local_filename = os.path.join(cachedir, filename)
-
-        if typ == 'tools':
-            if os.path.exists(local_filename):
-                print('Extract: %s' % local_filename)
-                zf = MyZipFile(local_filename)
-                zf.extractall(sdkdir)
-        elif typ == 'platform-tools':
-            if (sdkloc is None) and (os.path.exists(local_filename)):
-                print('Extract: %s' % local_filename)
-                zf = MyZipFile(local_filename)
-                zf.extractall(sdkdir)
-            else:
-                print('Link to: %s' % sdkloc)
-                os.symlink(sdkloc + '/platform-tools',
-                           sdkdir + '/platform-tools')
-        elif typ == 'platform':
-            if (sdkloc is None) and (os.path.exists(local_filename)):
-                print('Extract: %s' % local_filename)
-                zf = MyZipFile(local_filename)
-                zf.extractall(sdkdir + '/platforms')
-            else:
-                print('Link to: %s' % sdkloc)
-                os.symlink(sdkloc + '/platforms', sdkdir + '/platforms')
-        elif typ == 'build-tools':
-            if (sdkloc is None) and (os.path.exists(local_filename)):
-                print('Extract: %s' % local_filename)
-                zf = MyZipFile(local_filename)
-                zf.extractall(sdkdir + '/build-tools')
-            else:
-                print('Link to: %s' % sdkloc)
-                os.symlink(sdkloc + '/build-tools', sdkdir + '/build-tools')
-        elif typ == 'ndk':
-            if ndkloc is None:
-                print('Extract: %s' % local_filename)
-                zf = MyZipFile(local_filename)
-                zf.extractall(sdkdir)
-                lst = glob.glob(sdkdir + '/*-ndk-*')
-                print(lst)
-                os.rename(lst[0], sdkdir + '/ndk-bundle')
-            else:
-                print('Link to: %s' % ndkloc)
-                os.symlink(ndkloc, sdkdir + '/ndk-bundle')
-
-
-logger = logging.getLogger('prepare-fdroid-build')
-logging.basicConfig(format='%(message)s', level=logging.INFO)
-logger.setLevel(logging.INFO)
-
-# command line arguments
-
-sdkloc = None
-ndkloc = None
-if len(sys.argv) > 1:
-    sdkloc = sys.argv[1]
-    if (len(sdkloc) > 0) and (sdkloc[-1] == '/'):
-        sdkloc = sdkloc[:-1]
-    if not os.path.isdir(sdkloc):
-        sdkloc = None
-
-if len(sys.argv) > 2:
-    ndkloc = sys.argv[2]
-    if (len(ndkloc) > 0) and (ndkloc[-1] == '/'):
-        ndkloc = ndkloc[:-1]
-    if not os.path.isdir(ndkloc):
-        ndkloc = None
-
-fdroidmode = None
-if len(sys.argv) > 3:
-    fdroidmode = sys.argv[3]
-    if (len(fdroidmode) > 0):
-        fdroidmode = '1'
-
-if sdkloc == "":
-    sdkloc = None
-if ndkloc == "":
-    ndkloc = None
-
-logger.info('sdkloc = %s' % sdkloc)
-logger.info('ndkloc = %s' % ndkloc)
-
-# sdkloc and ndkloc already set by the user and fdroidmode:
-# nothing to do.
-
-if (sdkloc is not None) and (ndkloc is not None) and (fdroidmode is not None):
-    sys.exit(0)
-
-# cache dir (using the same as in fdroidserver/buildserver)
-cachedir = os.path.join(os.getenv('HOME'), '.cache', 'fdroidserver')
-logger.info('cachedir name is: %s', cachedir)
-
-if not os.path.exists(cachedir):
-    os.makedirs(cachedir, 0o755)
-    logger.info('created cachedir %s', cachedir)
-
-# sdkdir location
-sdkdir = os.path.join(os.getenv('HOME'), '.cache', 'sdk-for-p4a')
-logger.info('sdkdir name is: %s', sdkdir)
-
-if not os.path.exists(sdkdir):
-    os.makedirs(sdkdir, 0o755)
-    logger.debug('created sdkdir %s', sdkdir)
-
-    update_cache(cachedir, cachefiles)
-    build_sdk(sdkdir, cachedir, cachefiles)
-else:
-    logger.info('sdkdir %s already exists', sdkdir)
diff --git a/android/main.py b/android/main.py
index f98f6d64..c3dac4bd 100755
--- a/android/main.py
+++ b/android/main.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python3
 # ---------------------------------------------------------------------------
 #
 # PySol -- a Python Solitaire game
diff --git a/android/mkcards b/android/mkcards
index b996897e..c1a31cdd 100755
--- a/android/mkcards
+++ b/android/mkcards
@@ -1,46 +1,27 @@
 #!/bin/bash
+set -eux
+
+. mkp4a.common
 
 echo '### prepare cardsets'
 
-if [ ! -f ./PySolFC-Cardsets-2.0.tar.bz2 ]
-then
-  echo '### downloading cardets'
-  # wget http://downloads.sourceforge.net/pysolfc/PySolFC-Cardsets-2.0.tar.bz2
-  wget https://netix.dl.sourceforge.net/project/pysolfc/PySolFC-Cardsets/PySolFC-Cardsets-2.0/PySolFC-Cardsets-2.0.tar.bz2
+if [ ! -f ${cardsets_file} ]; then
+  echo '### downloading cardsets'
+  wget https://netix.dl.sourceforge.net/project/pysolfc/PySolFC-Cardsets/minimal/${cardsets_file}
 fi
 
-if [ -f ./PySolFC-Cardsets-2.0.tar.bz2 ]
-then
-  if [ ! -d ./PySolFC-Cardsets-2.0 ]
-  then
-    echo '### extracting selected cardets'
-    tar -xjvf PySolFC-Cardsets-2.0.tar.bz2 \
-PySolFC-Cardsets-2.0/cardset-crystal-mahjongg \
-PySolFC-Cardsets-2.0/cardset-dashavatara-ganjifa \
-PySolFC-Cardsets-2.0/cardset-dondorf \
-PySolFC-Cardsets-2.0/cardset-hexadeck \
-PySolFC-Cardsets-2.0/cardset-kintengu \
-PySolFC-Cardsets-2.0/cardset-matrix \
-PySolFC-Cardsets-2.0/cardset-mughal-ganjifa \
-PySolFC-Cardsets-2.0/cardset-oxymoron \
-PySolFC-Cardsets-2.0/cardset-standard \
-PySolFC-Cardsets-2.0/cardset-vienna-2k \
-PySolFC-Cardsets-2.0/cardset-greywyvern
-  fi
-
-  if [ -d ./PySolFC-Cardsets-2.0 ]
-  then
-    echo '### processing cardets'
-    cd PySolFC-Cardsets-2.0
-    ../../scripts/cardsetsgiftobmp
-    for i in cardset-*-bmp
-    do
-      rm -rf `basename $i -bmp`
-    done
-    cd ..
-  fi
-else
-  echo '### error downloading cardsets'
+if [ ! -d ${cardsets_dir} ]; then
+  echo '### extracting cardsets'
+  tar -xf ${cardsets_file}
 fi
 
+echo '### processing cardsets'
+(
+  cd ${cardsets_dir}
+  ../../scripts/cardconv
+  for i in cardset-*-bmp; do
+    rm -rf `basename $i -bmp`
+  done
+)
+
 echo '### end cardsets'
diff --git a/android/mkkeystore b/android/mkkeystore
index f825daa1..cbdba26d 100755
--- a/android/mkkeystore
+++ b/android/mkkeystore
@@ -1,16 +1,12 @@
 #!/bin/bash
+set -eux
 
 # memo:
 # keytool -genkey -v -keystore my-release-keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 12000
 
-if [ ! -d bin ]
-then
-  echo "mkdir bin"
-  mkdir bin
-fi
+mkdir -p bin
 
-if [ -f ./bin/keystore ]
-then
+if [ -f ./bin/keystore ]; then
   echo "keystore is already defined"
 else
   keytool -genkey -v -keystore ./bin/keystore -alias python -keyalg RSA -keysize 2048 -validity 12000
diff --git a/android/mkp4a.clean b/android/mkp4a.clean
index bc46fe42..c558eaef 100755
--- a/android/mkp4a.clean
+++ b/android/mkp4a.clean
@@ -1,8 +1,8 @@
 #!/bin/bash
+set -eux
 
 rm -rf tmp
 python3 -m pythonforandroid.toolchain clean_dists
 python3 -m pythonforandroid.toolchain clean_builds
 rm -f *.apk
-rm -rf PySolFC-Cardsets-2.0
-
+rm -rf PySolFC-Cardsets--Minimal-2.0.1
diff --git a/android/mkp4a.cleanall b/android/mkp4a.cleanall
index 34ef7480..ad1d4bdf 100755
--- a/android/mkp4a.cleanall
+++ b/android/mkp4a.cleanall
@@ -1,4 +1,5 @@
 #!/bin/bash
+set -e
 
 rm -rf tmp
 rm -f *.apk
diff --git a/android/mkp4a.common b/android/mkp4a.common
new file mode 100644
index 00000000..46e05f7f
--- /dev/null
+++ b/android/mkp4a.common
@@ -0,0 +1,28 @@
+# Common constants for various scripts in this directory.
+
+version=$(PYTHONPATH=.. python3 -c \
+  'from pysollib.settings import VERSION; print(VERSION)')
+
+tmpdir=${HOME}/.cache/tmp-for-p4a/pysolfc/src
+
+cardsets_dir='PySolFC-Cardsets--Minimal-2.0.1'
+cardsets_file="${cardsets_dir}.tar.xz"
+
+sdkdir="${HOME}/.cache/sdk-for-p4a/sdk"
+ndkdir="${HOME}/.cache/sdk-for-p4a/android-ndk-r17c"
+
+p4a_options="\
+  --sdk-dir ${sdkdir} \
+  --ndk-dir ${ndkdir} \
+  --dist-name pysolfc \
+  --name PySolFC \
+  --package org.lufebe16.pysolfc \
+  --version ${version} \
+  --bootstrap sdl2 \
+  --requirements python3,attrs,configobj,kivy,pysol-cards,random2,six \
+  --private ${tmpdir} \
+  --orientation sensor \
+  --icon ${tmpdir}/data/images/icons/48x48/pysol.png \
+  --presplash ${tmpdir}/data/images/icons/1024x1024/pysol.png \
+  --copy-libs \
+  --color always"
diff --git a/android/mkp4a.debug b/android/mkp4a.debug
index 04ba2130..4256c6d5 100755
--- a/android/mkp4a.debug
+++ b/android/mkp4a.debug
@@ -1,32 +1,11 @@
 #!/bin/bash
+set -eux
 
-package='org.lufebe16.pysolfc'
-version=`./version.py`
-name='PySolFC'
-tmpdir=${HOME}/.cache/tmp-for-p4a/pysolfc/src
+. mkp4a.common
 
-if [ "$1" ]
-then
-  package=${package}.dbg
-  name=${name}dbg
-fi
+new_options=${p4a_options}
+new_options=${new_options/PySolFC/PySolFCdbg}
+new_options=${new_options/org.lubefe16.pysolfc/org.lubefe16.pysolfc.dbg}
 
 python3 -m pythonforandroid.toolchain apk \
-  --sdk-dir ${HOME}/.cache/sdk-for-p4a \
-  --ndk-dir ${HOME}/.cache/sdk-for-p4a/ndk-bundle \
-  --android-api 19 \
-  --ndk-version r12b \
-  --arch armeabi-v7a \
-  --dist-name pysolfc \
-  --name ${name} \
-  --bootstrap=sdl2 \
-  --requirements kivy,hostpython2,random2 \
-  --minsdk 14 \
-  --private ${tmpdir} \
-  --package ${package} \
-  --version ${version} \
-  --orientation sensor \
-  --color=always \
-  --icon ${tmpdir}/data/images/icons/48x48/pysol.png \
-  --presplash ${tmpdir}/data/images/icons/1024x1024/pysol.png \
-  --copy-libs
+  ${new_options}
diff --git a/android/mkp4a.init b/android/mkp4a.init
index 108012a1..2cb81d4f 100755
--- a/android/mkp4a.init
+++ b/android/mkp4a.init
@@ -1,56 +1,33 @@
 #!/bin/bash
+set -eux
+
+. mkp4a.common
 
 echo '### prepare sdk'
 
-./initsdk.py $1 $2 $3
+./initsdk
 
 echo '### install p4a'
 
-p4adir=${HOME}/.cache/tmp-for-p4a
-mkdir -p ${p4adir}
-
-p4aversion='0.5.3'
-if [ ! -f ${p4adir}/${p4aversion}.zip ]
-then
-  wget "https://github.com/kivy/python-for-android/archive/${p4aversion}.zip"
-  cp -a ./${p4aversion}.zip ${p4adir}/${p4aversion}.zip
-  rm -f ./${p4aversion}.zip
-fi
-if [ -f ${p4adir}/${p4aversion}.zip ]
-then
-  python3 -m  pip install -q --user "${p4adir}/${p4aversion}.zip"
-else
-  echo "### download of ${p4aversion}.zip failed"
-fi
+python3 -m pip install -q --user python-for-android
 
 echo '### prepare source'
 
-srcdir=${HOME}/.cache/tmp-for-p4a/pysolfc/src
+(cd .. && make rules)
 
-mkdir -p ${srcdir}
-rm -rf ${srcdir}
-cp -a .. ${srcdir}
-rm -rf ${srcdir}/android
-rm -rf ${srcdir}/src
-cp -a main.py ${srcdir}/main.py
-mkdir -p ${srcdir}/data/images/cards/bottoms/trumps-only
-echo "" > ${srcdir}/data/images/cards/bottoms/trumps-only/.keep
+mkdir -p ${tmpdir}
+rm -rf ${tmpdir}
+cp -a .. ${tmpdir}
+rm -rf ${tmpdir}/android
+rm -rf ${tmpdir}/src
+cp -a main.py ${tmpdir}
+mkdir -p ${tmpdir}/data/images/cards/bottoms/trumps-only
+echo "" > ${tmpdir}/data/images/cards/bottoms/trumps-only/.keep
 
 echo '### prepare cardsets'
 
-cardsdir=${HOME}/.cache/tmp-for-p4a/pysolfc
+./mkcards
 
-if [ ! -d ${cardsdir}/PySolFC-Cardsets-2.0 ]
-then
-  ./mkcards
-  mv PySolFC-Cardsets-2.0 ${cardsdir}/
-  rm -f PySolFC-Cardsets-2.0.tar.bz2
-fi
-
-if [ -d ${cardsdir}/PySolFC-Cardsets-2.0 ]
-then
-  echo '### copying cardsets'
-  cp -a ${cardsdir}/PySolFC-Cardsets-2.0/* ${srcdir}/data
-fi
+cp -a ${cardsets_dir}/* ${tmpdir}/data
 
 echo '### end init'
diff --git a/android/mkp4a.release b/android/mkp4a.release
index 4769bda1..541c92cc 100755
--- a/android/mkp4a.release
+++ b/android/mkp4a.release
@@ -1,11 +1,13 @@
 #!/bin/bash
+set -e
+
+. mkp4a.common
 
 pass1=""
 pass2=""
 keyalias="python"
 keystore="${PWD}/bin/keystore"
-if [ $1 ]
-then
+if [ $1 ]; then
   pass1=$1
   pass2=$1
 else
@@ -13,16 +15,13 @@ else
   echo "        (use ./mkkeystore to create one in default location)"
   exit
 fi
-if [ $2 ]
-then
+if [ $2 ]; then
   pass2=$2
 fi
-if [ $3 ]
-then
+if [ $3 ]; then
   keyalias=$3
 fi
-if [ $4 ]
-then
+if [ $4 ]; then
   keystore=$4
 fi
 
@@ -31,30 +30,10 @@ export P4A_RELEASE_KEYSTORE_PASSWD="$pass1"
 export P4A_RELEASE_KEYALIAS_PASSWD="$pass2"
 export P4A_RELEASE_KEYALIAS="$keyalias"
 
-version=`./version.py`
-tmpdir=${HOME}/.cache/tmp-for-p4a/pysolfc/src
-
 python3 -m pythonforandroid.toolchain apk \
-  --sdk-dir ${HOME}/.cache/sdk-for-p4a \
-  --ndk-dir ${HOME}/.cache/sdk-for-p4a/ndk-bundle \
-  --android-api 19 \
-  --ndk-version r12b \
-  --arch armeabi-v7a \
-  --dist-name pysolfc \
-  --name PySolFC \
-  --bootstrap=sdl2 \
-  --requirements kivy,hostpython2,random2 \
+  ${p4a_options} \
   --release \
-  --sign \
-  --minsdk 14 \
-  --private ${tmpdir} \
-  --package org.lufebe16.pysolfc \
-  --version ${version} \
-  --orientation sensor \
-  --color=always \
-  --icon ${tmpdir}/data/images/icons/48x48/pysol.png \
-  --presplash ${tmpdir}/data/images/icons/1024x1024/pysol.png \
-  --copy-libs
+  --sign
 
 # keystore options (instead environment vars):
 #
diff --git a/android/mkp4a.unsigned b/android/mkp4a.unsigned
index 5c18b256..845ef729 100755
--- a/android/mkp4a.unsigned
+++ b/android/mkp4a.unsigned
@@ -1,47 +1,11 @@
 #!/bin/bash
+set -eux
 
-echo '### p4a started'
-
-# sdk-dir and nkd-dir from command line (fdroid mode)
-
-sdkdir="${HOME}/.cache/sdk-for-p4a"
-ndkdir="${HOME}/.cache/sdk-for-p4a/ndk-bundle"
-if [ $1 ]
-then
-  echo "set sdk to: $1"
-  sdkdir="$1"
-fi
-if [ $2 ]
-then
-  echo "set ndk to: $2"
-  ndkdir="$2"
-fi
-
-echo '### run toolchain'
-
-version=`./version.py`
-tmpdir=${HOME}/.cache/tmp-for-p4a/pysolfc/src
+. mkp4a.common
 
 python3 -m pythonforandroid.toolchain apk \
-  --sdk-dir ${sdkdir} \
-  --ndk-dir ${ndkdir} \
-  --android-api 19 \
-  --ndk-version r12b \
-  --arch armeabi-v7a \
-  --dist-name pysolfc \
-  --name PySolFC \
-  --bootstrap=sdl2 \
-  --requirements kivy,hostpython2,random2 \
-  --release \
-  --minsdk 14 \
-  --private ${tmpdir} \
-  --package org.lufebe16.pysolfc \
-  --version ${version} \
-  --orientation sensor \
-  --color=always \
-  --icon ${tmpdir}/data/images/icons/48x48/pysol.png \
-  --presplash ${tmpdir}/data/images/icons/1024x1024/pysol.png \
-  --copy-libs
+  ${p4a_options} \
+  --release
 
 # python3 -m pythonforandroid.toolchain apk
 # ...
@@ -53,5 +17,3 @@ python3 -m pythonforandroid.toolchain apk \
 # ohne:    -> debug version
 # 1:       -> release unsigned
 # 1 und 2: -> release version.
-
-echo '### p4a finished'
diff --git a/contrib/install-pysolfc.sh b/contrib/install-pysolfc.sh
index 8fa52213..1d2e13f7 100755
--- a/contrib/install-pysolfc.sh
+++ b/contrib/install-pysolfc.sh
@@ -1,4 +1,5 @@
-#! /bin/sh -Cefu
+#!/bin/sh
+set -Cefu
 
 : ${PKGTREE:=/usr/local/packages/PySolFC}
 PIP="$(printf '%s/env/bin/pip install --no-binary :all: ' "$PKGTREE")"
diff --git a/data/procexample.txt b/data/procexample.txt
index cc225ff2..ce1660a4 100755
--- a/data/procexample.txt
+++ b/data/procexample.txt
@@ -1,4 +1,6 @@
 #!/bin/bash
+set -e
+
 # convert gif to png - dir recursive
 
 # scharf !!!!
diff --git a/data/themes/clearlooks/convert_imgs.sh b/data/themes/clearlooks/convert_imgs.sh
index ae8ed9ea..11992d3b 100755
--- a/data/themes/clearlooks/convert_imgs.sh
+++ b/data/themes/clearlooks/convert_imgs.sh
@@ -1,4 +1,5 @@
 #!/bin/sh
+set -e
 
 from_dir=images
 to_dir=clearlooks
diff --git a/scripts/cardconv b/scripts/cardconv
index 7ed8e7ba..d165a1e1 100755
--- a/scripts/cardconv
+++ b/scripts/cardconv
@@ -1,39 +1,55 @@
 #!/bin/bash
+set -eu
 
-# converts cardset images and config files in current
-# directory from input-format to output-format.
+# Converts cardset images and config files in subdirs of the current
+# directory from input-format to output-format (default: gif to bmp).
 #
-# example to convert from gif format to png:
+# Example to convert from gif format to png:
 #
 # $> cardconv gif png
 #
-# needs package 'ImageMagick' beeing installed.
+# Needs package 'ImageMagick' being installed.
 
-ifo=''
-if [ $1 ]
-then
+ifo='gif'
+ofo='bmp'
+
+if [ $# -eq 2 ]; then
   ifo=$1
-else
-  echo 'use: cardconv <input-format> <output-format>'
-  exit
-fi
-
-ofo=''
-if [ $2 ]
-then
   ofo=$2
-else
-  echo 'use: cardconv <input-format> <output-format>'
-  exit
+elif [ $# -ne 0 ]; then
+  echo "Usage: cardconv [INPUTFORMAT OUTPUTFORMAT]"
+  echo "If formats are not specified, converts $ifo to $ofo."
+  exit 1
 fi
 
-# alle images.
-for i in *.${ifo}; do convert $i `basename $i .${ifo}`.${ofo}; rm -f $i; done
+# Returns true if $1/config.txt exists and contains a mention of the input format
+# file extension.
+chkdir() {
+  grep -qi "\.${ifo}" "${1}/config".txt
+  return $?
+}
 
-# config.txt
-if [ -f config.txt ]
-then
-  cp -a config.txt tmp.txt
-  cat tmp.txt | sed "s/.${ifo}/.${ofo}/g" >config.txt
-  rm -f tmp.txt
-fi
+# Usage: convdir in_dir out_dir
+convdir() {
+  mkdir -p "$2"
+
+  # Convert all images
+  for i in $1/*.$ifo; do
+    convert "$i" "$2/$(basename $i .$ifo).$ofo"
+  done
+
+  # Convert config.txt
+  if [ -f $1/config.txt ]; then
+    sed "s/\.${ifo}/.${ofo}/g" $1/config.txt > $2/config.txt
+  fi
+}
+
+# Check all cardsets.
+for in_dir in cardset-*; do
+  out_dir=${in_dir}-${ofo}
+
+  if [[ ! $in_dir =~ -$ofo$ ]] && [ ! -d $out_dir ] && chkdir $in_dir; then
+    convdir $in_dir $out_dir
+    echo "$out_dir created"
+  fi
+done
diff --git a/scripts/cardsetsgiftobmp b/scripts/cardsetsgiftobmp
deleted file mode 100755
index 1b0ecefa..00000000
--- a/scripts/cardsetsgiftobmp
+++ /dev/null
@@ -1,77 +0,0 @@
-#!/bin/bash
-
-# creates a bmp copy off all gif cardsets in the current dir.
-# uses package 'ImageMagick'
-
-ifo='gif'
-if [ $1 ]
-then
-  ifo=$1
-fi
-
-ofo='bmp'
-if [ $2 ]
-then
-  ofo=$2
-fi
-
-function chkdir()
-{
-  # convert all images
-  cd $1
-  if [ -f config.txt ]
-  then
-    g=`grep -i ".${ifo}" config.txt`
-    #echo $g
-    if [[ $g == "" ]]
-    then
-      cd ..
-      return 1
-    else
-      cd ..
-      return 0
-    fi
-  fi
-  cd ..
-  return 0
-}
-
-function convdir()
-{
-  # convert all images
-  for i in *.${ifo}; do convert $i `basename $i .${ifo}`.${ofo}; rm -f $i; done
-
-  # convert config.txt
-  if [ -f config.txt ]
-  then
-    cp -a config.txt tmp.txt
-    cat tmp.txt | sed "s/.${ifo}/.${ofo}/g" >config.txt
-    rm -f tmp.txt
-  fi
-}
-
-# check all cardsets.
-
-for k in cardset-*
-do
-  x=${k%-bmp}
-  y=$x-${ofo}
-
-  if chkdir $k
-  then
-    if [ $k != $y ]
-    then
-      if [ -a $y ]
-      then
-    	  echo "$y exists already - skipped"
-      else
-    	  echo "$y processing ..."
-        cp -a $k $y
-        cd $y
-        convdir
-        cd ..
-    	  echo "$y created"
-      fi
-    fi
-  fi
-done
diff --git a/scripts/test-inside-dist.sh b/scripts/test-inside-dist.sh
index 484d319c..2586c665 100644
--- a/scripts/test-inside-dist.sh
+++ b/scripts/test-inside-dist.sh
@@ -1,4 +1,6 @@
 #! /bin/sh
+set -e
+
 #
 # y.sh
 # Copyright (C) 2018 shlomif <shlomif@cpan.org>
diff --git a/scripts/travis-ci-build b/scripts/travis-ci-build
index ab72c27d..5cf0ed7b 100644
--- a/scripts/travis-ci-build
+++ b/scripts/travis-ci-build
@@ -1,10 +1,12 @@
 #!/bin/bash
+set -e
+
 # Functioned-out - may be useful later.
 proc_path()
 {
     PATH="$(perl -lE 'my @p = split/:/,$ENV{PATH}; print join q#:#, grep { ! m#\A/opt/python# } @p;')" "$@"
 }
-make test || exit -1
-make dist || exit -1
-tar -xvf dist/PySolFC-*.tar.xz || exit -1
-(cd PySolFC-*/ && make test) || exit -1
+make test
+make dist
+tar -xvf dist/PySolFC-*.tar.xz
+(cd PySolFC-*/ && make test)