From 20e6574c8c138482d69b5ce9a75bfb79def3413c Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sun, 3 May 2020 13:11:29 +0200
Subject: [PATCH 1/2] Use pre-compiled CMake.

---
 docker/cmake.sh | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/docker/cmake.sh b/docker/cmake.sh
index 8aa097543..6c2ef8f01 100755
--- a/docker/cmake.sh
+++ b/docker/cmake.sh
@@ -4,21 +4,15 @@ set -x
 set -euo pipefail
 
 main() {
-    local version=3.16.5
+    local version=3.17.2
 
-    local dependencies=(
-        curl
-        g++
-        libssl-dev
-        make
-        zlib1g-dev
-    )
+    local dependencies=(curl)
 
     apt-get update
     local purge_list=()
     for dep in ${dependencies[@]}; do
         if ! dpkg -L $dep; then
-            apt-get install --no-install-recommends --assume-yes $dep
+            apt-get install --assume-yes --no-install-recommends $dep
             purge_list+=( $dep )
         fi
     done
@@ -27,21 +21,17 @@ main() {
 
     pushd $td
 
-    curl https://cmake.org/files/v${version%.*}/cmake-$version.tar.gz | \
-        tar --strip-components 1 -xz
+    curl -sSfL "https://github.com/Kitware/CMake/releases/download/v${version}/cmake-${version}-Linux-x86_64.sh" -o cmake.sh
+    sh cmake.sh --skip-license --prefix=/usr/local
 
-    ./bootstrap
-    make -j$(nproc)
-    make install
-
-    # clean up
     popd
 
     if (( ${#purge_list[@]} )); then
-      apt-get purge --auto-remove -y ${purge_list[@]}
+      apt-get purge --assume-yes --auto-remove ${purge_list[@]}
     fi
 
     rm -rf $td
+    rm -rf /var/lib/apt/lists/*
     rm $0
 }
 

From a4c1f45b2c56290b24c1cf51c5cc4c889bb45ae2 Mon Sep 17 00:00:00 2001
From: Markus Reiter <me@reitermark.us>
Date: Sun, 3 May 2020 13:12:27 +0200
Subject: [PATCH 2/2] Only use `--cache-from` if image was pulled.

---
 build-docker-image.sh | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/build-docker-image.sh b/build-docker-image.sh
index 2d1a95b69..7d43eeccb 100755
--- a/build-docker-image.sh
+++ b/build-docker-image.sh
@@ -10,8 +10,10 @@ run() {
   local image_name="rustembedded/cross:${1}"
   local cache_from_args=
 
-  if docker image inspect "${image_name}" &>/dev/null || docker pull "${image_name}"; then
-    cache_from_args=(--cache-from "${image_name}")
+  if ! docker image inspect "${image_name}" &>/dev/null; then
+    if docker pull "${image_name}"; then
+      cache_from_args=(--cache-from "${image_name}")
+    fi
   fi
 
   docker build ${cache_from_args[@]} --pull -t "${image_name}" -f "${dockerfile}" .