GitHub Actions: add Linux Qt 5.12 container build

The AppImage works - I just need to figure out how to post releases. For now
it'a available on the Actions page as Artifact.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

.github/workflows/in-container-build.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+set -x
+set -e
+
+# this gets executed by Travis when building an AppImage for Linux
+# inside of the trusty-qt512 container
+
+export PATH=$QT_ROOT/bin:$PATH # Make sure correct qmake is found on the $PATH for linuxdeployqt
+export CMAKE_PREFIX_PATH=$QT_ROOT/lib/cmake
+export Grantlee5_ROOT=/__w/subsurface/subsurface/install-root
+
+# the container currently has things under / that need to be under /__w/subsurface/subsurface instead
+cp -a /appdir /__w/subsurface/subsurface/
+cp -a /install-root /__w/subsurface/subsurface/
+
+# first make sure that no one broke Subsurface-mobile
+bash -e -x subsurface/scripts/build.sh -mobile -quick
+
+# now build our AppImage
+bash -e -x subsurface/scripts/build.sh -desktop -create-appdir -build-with-webkit -quick
+
+export QT_PLUGIN_PATH=$QT_ROOT/plugins
+export QT_QPA_PLATFORM_PLUGIN_PATH=$QT_ROOT/plugins
+export QT_DEBUG_PLUGINS=1
+
+# set up the appdir
+mkdir -p appdir/usr/plugins/
+
+# mv googlemaps and Grantlee plugins into place
+mv appdir/usr/usr/local/Qt/5.12.4/gcc_64/plugins/* appdir/usr/plugins  # the usr/usr is not a typo, that's where it ends up
+mv appdir/usr/lib/grantlee/ appdir/usr/plugins/
+rm -rf appdir/usr/home/ appdir/usr/include/ appdir/usr/share/man/ # No need to ship developer and man files as part of the AppImage
+rm -rf appdir/usr/usr appdir/usr/lib/cmake appdir/usr/lib/pkgconfig
+cp /ssllibs/libssl.so appdir/usr/lib/libssl.so.1.1
+cp /ssllibs/libcrypto.so appdir/usr/lib/libcrypto.so.1.1
+
+# get the linuxdeployqt tool and run it to collect the libraries
+curl -L -O "https://github.com/probonopd/linuxdeployqt/releases/download/continuous/linuxdeployqt-continuous-x86_64.AppImage"
+chmod a+x linuxdeployqt*.AppImage
+unset QTDIR
+unset QT_PLUGIN_PATH
+unset LD_LIBRARY_PATH
+./linuxdeployqt*.AppImage --appimage-extract-and-run ./appdir/usr/share/applications/*.desktop -bundle-non-qt-libs -qmldir=./subsurface/map-widget/ -verbose=2
+
+# create the AppImage
+export VERSION=$(cd subsurface/scripts ; ./get-version linux) # linuxdeployqt uses this for naming the file
+./linuxdeployqt*.AppImage --appimage-extract-and-run ./appdir/usr/share/applications/*.desktop -appimage -qmldir=./subsurface/map-widget/ -verbose=2
+
+# copy AppImage to the calling VM
+# with GitHub Actions the /${GITHUB_WORKSPACE} directory is the current working directory at the start of a step
+cp Subsurface*.AppImage* /${GITHUB_WORKSPACE}/Subsurface.AppImage
+ls -l /${GITHUB_WORKSPACE}/Subsurface.AppImage

.github/workflows/linux-trusty-5.12.yml

@@ -0,0 +1,27 @@
+name: Linux Qt 5.12
+on: push
+
+jobs:
+  buildInContainer:
+    runs-on: ubuntu-latest
+    container:
+      image: docker://dirkhh/trusty-qt512:0.7
+
+    steps:
+    - name: checkout sources
+      run: |
+        echo $pwd
+        git clone git://github.com/${GITHUB_REPOSITORY}
+        cd subsurface
+        git checkout ${GITHUB_SHA}
+
+    - name: run build
+      run: |
+        echo $pwd
+        bash -x subsurface/.github/workflows/in-container-build.sh
+
+    - name: publish result
+      uses: actions/upload-artifact@v1
+      with:
+        name: Subsurface-${{github.sha}}.AppImage
+        path: ./Subsurface.AppImage  # /${GITHUB_WORKSPACE}/ in the container is '.' here

CMakeLists.txt

@@ -11,6 +11,11 @@ if (POLICY CMP0071)
 	cmake_policy(SET CMP0071 OLD)
 endif()
 
+# support Packagename_ROOT environment variable
+if (POLICY CMP0074)
+  cmake_policy(SET CMP0074 NEW) # CMake 3.12
+endif ()
+
 # global settings
 
 set(CMAKE_MODULE_PATH