explicit setup of ccache

.ci/travis/linux/script.sh

@@ -19,8 +19,7 @@ DIR=$(git rev-parse --show-toplevel)/.docker
 
 docker-compose -f $DOCKER_COMPOSE run --rm qgis-deps
 
-ccachedir=${HOME}/.ccache
-mkdir -p $ccachedir
+mkdir -p $CCACHE_DIR
 
 docker-compose -f $DOCKER_COMPOSE run --rm qgis-deps
 

.docker/docker-compose.travis.yml

@@ -8,10 +8,11 @@ services:
     image: qgis/qgis3-build-deps:${DOCKER_TAG}
     volumes:
       - ${TRAVIS_BUILD_DIR}:/root/QGIS
-      - $HOME/.ccache:/root/.ccache
+      - $HOME/.ccache:/root/.ccache  # if changed, also change env var
     links:
       - postgres
     environment:
+      - CCACHE_DIR=/root/.ccache
       - TRAVIS_BUILD_DIR=${TRAVIS_BUILD_DIR}
       - TRAVIS_PULL_REQUEST=${TRAVIS_PULL_REQUEST}
       - TRAVIS_PULL_REQUEST_BRANCH=${TRAVIS_PULL_REQUEST_BRANCH}

.travis.yml

@@ -10,7 +10,7 @@ matrix:
         - DOCKER_COMPOSE=${TRAVIS_BUILD_DIR}/.docker/docker-compose.travis.yml
         - DOCKER_TAG=$( [[ $TRAVIS_REPO_SLUG =~ qgis/QGIS ]] && echo $TRAVIS_BRANCH | sed 's/master/latest/' || echo "latest" )
         - DOCKER_PUSH=$( [[ $TRAVIS_REPO_SLUG =~ qgis/QGIS ]] && [[ $TRAVIS_PULL_REQUEST =~ false ]] && echo "true" || echo "false" )
-
+        - CCACHE_DIR=${HOME}/.ccache
       dist: trusty
       sudo: false
       cache: