Updated drone recipe

.drone.yml

@@ -1,52 +1,100 @@
 pipeline:
   gcc5:
-    image: gcc:5
+    image: debian:jessie-slim
     pull: true
+    environment:
+      - CXX=g++-5
+      - CXXFLAGS=-pipe -O2
     commands:
-      - echo "deb http://deb.debian.org/debian stretch main" >> /etc/apt/sources.list.d/stretch.list
+      - rm /etc/apt/apt.conf.d/docker-clean
       - echo "APT::Default-Release \"jessie\";" >> /etc/apt/apt.conf.d/00default_release
+      - echo "deb http://deb.debian.org/debian jessie-backports main" >> /etc/apt/sources.list.d/backports.list
+      - echo "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu trusty main" >> /etc/apt/sources.list.d/ubuntu-toolchain-r.list
+      - gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0x60c317803a41ba51845e371a1e9377a2ba9ef27f
+      - gpg --armor --export 0x60c317803a41ba51845e371a1e9377a2ba9ef27f | apt-key add -
       - apt-get update -q
-      - apt-get install -qyt stretch cmake libjsoncpp-dev
-      - apt-get install -qy libxdg-basedir-dev
+      - apt-get install -qy -t trusty g++-5
+      - apt-get install -qy -t jessie-backports cmake libjsoncpp-dev
+      - apt-get install -qy pkg-config libxdg-basedir-dev
       - rm -rf build && mkdir -p build && cd build
       - cmake ..
       - make VERBOSE=1
       - make install DESTDIR=install
+    volumes:
+      - /var/cache/debian-package-cache:/var/cache/apt/archives
+
   gcc6:
-    image: gcc:6
+    image: debian:jessie-slim
     pull: true
+    environment:
+      - CXX=g++-6
+      - CXXFLAGS=-pipe -O2
     commands:
-      - echo "deb http://deb.debian.org/debian stretch main" >> /etc/apt/sources.list.d/stretch.list
+      - rm /etc/apt/apt.conf.d/docker-clean
       - echo "APT::Default-Release \"jessie\";" >> /etc/apt/apt.conf.d/00default_release
+      - echo "deb http://deb.debian.org/debian jessie-backports main" >> /etc/apt/sources.list.d/backports.list
+      - echo "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu trusty main" >> /etc/apt/sources.list.d/ubuntu-toolchain-r.list
+      - gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0x60c317803a41ba51845e371a1e9377a2ba9ef27f
+      - gpg --armor --export 0x60c317803a41ba51845e371a1e9377a2ba9ef27f | apt-key add -
       - apt-get update -q
-      - apt-get install -qyt stretch cmake libjsoncpp-dev
-      - apt-get install -qy libxdg-basedir-dev
+      - apt-get install -qy -t trusty g++-6
+      - apt-get install -qy -t jessie-backports cmake libjsoncpp-dev
+      - apt-get install -qy pkg-config libxdg-basedir-dev
       - rm -rf build && mkdir -p build && cd build
       - cmake ..
       - make VERBOSE=1
       - make install DESTDIR=install
+    volumes:
+      - /var/cache/debian-package-cache:/var/cache/apt/archives
+
   gcc7:
-    image: gcc:7
+    image: debian:jessie-slim
     pull: true
+    environment:
+      - CXX=g++-7
+      - CXXFLAGS=-pipe -O2
     commands:
+      - rm /etc/apt/apt.conf.d/docker-clean
+      - echo "APT::Default-Release \"jessie\";" >> /etc/apt/apt.conf.d/00default_release
+      - echo "deb http://deb.debian.org/debian jessie-backports main" >> /etc/apt/sources.list.d/backports.list
+      - echo "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu trusty main" >> /etc/apt/sources.list.d/ubuntu-toolchain-r.list
+      - gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0x60c317803a41ba51845e371a1e9377a2ba9ef27f
+      - gpg --armor --export 0x60c317803a41ba51845e371a1e9377a2ba9ef27f | apt-key add -
       - apt-get update -q
-      - apt-get install -qyt stretch cmake
-      - apt-get install -qy libjsoncpp-dev libxdg-basedir-dev
+      - apt-get install -qy -t trusty g++-7
+      - apt-get install -qy -t jessie-backports cmake libjsoncpp-dev
+      - apt-get install -qy pkg-config libxdg-basedir-dev
       - rm -rf build && mkdir -p build && cd build
       - cmake ..
       - make VERBOSE=1
       - make install DESTDIR=install
+    volumes:
+      - /var/cache/debian-package-cache:/var/cache/apt/archives
+
   gcc8:
-    image: gcc:8
+    image: debian:jessie-slim
     pull: true
+    environment:
+      - CXX=g++-8
+      - CXXFLAGS=-pipe -O2
     commands:
+      - rm /etc/apt/apt.conf.d/docker-clean
+      - echo "APT::Default-Release \"jessie\";" >> /etc/apt/apt.conf.d/00default_release
+      - echo "deb http://deb.debian.org/debian jessie-backports main" >> /etc/apt/sources.list.d/backports.list
+      - echo "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu trusty main" >> /etc/apt/sources.list.d/ubuntu-toolchain-r.list
+      - gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys 0x60c317803a41ba51845e371a1e9377a2ba9ef27f
+      - gpg --armor --export 0x60c317803a41ba51845e371a1e9377a2ba9ef27f | apt-key add -
       - apt-get update -q
-      - apt-get install -qyt stretch cmake
-      - apt-get install -qy libjsoncpp-dev libxdg-basedir-dev
+      - apt-get install -qy -t trusty g++-8
+      - apt-get install -qy -t jessie-backports cmake libjsoncpp-dev
+      - apt-get install -qy pkg-config libxdg-basedir-dev
       - rm -rf build && mkdir -p build && cd build
       - cmake ..
       - make VERBOSE=1
       - make install DESTDIR=install
+    volumes:
+      - /var/cache/debian-package-cache:/var/cache/apt/archives
+
   notify:
     image: drillster/drone-email
     pull: true

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.7)
+cmake_minimum_required (VERSION 3.1)
 project(xdgjson
         VERSION 0.2.2
         LANGUAGES CXX