Upgrade requirement to cmake 3.6 because that's needed to build the range-v3 dependency (if built locally and not with a prebuilt conan package)

.circleci/config.yml

@@ -55,7 +55,21 @@ references:
         sudo chmod o-w /etc/apt/sources.list.d/clang.list
 
         DEBIAN_FRONTEND=noninteractive sudo apt-get update -qq
-        DEBIAN_FRONTEND=noninteractive sudo apt-get install -y git ccache $APT_COMPILER_PACKAGE cmake make libcurl4-openssl-dev libssl-dev libfuse-dev
+        DEBIAN_FRONTEND=noninteractive sudo apt-get install -y git ccache $APT_COMPILER_PACKAGE make libcurl4-openssl-dev libssl-dev libfuse-dev
+
+        # install cmake
+        wget -O /tmp/cmake.sh https://github.com/Kitware/CMake/releases/download/v3.6.3/cmake-3.6.3-Linux-x86_64.sh
+        if [ $(sha256sum /tmp/cmake.sh | awk '{print $1;}') == "a512fc991abf51ee8d309312e106daf11d1e6c9bd7dd1c15c2bd5f9ca820fa0f" ]; then
+          echo Correct sha256sum
+        else
+          echo Wrong sha256sum
+          sha256sum /tmp/cmake.sh
+          exit 1
+        fi
+        sudo mkdir /opt/cmake
+        sudo sh /tmp/cmake.sh --prefix=/opt/cmake --skip-license
+        sudo ln -s /opt/cmake/bin/cmake /usr/local/bin/cmake
+        cmake --version
 
         # install conan
         pyenv global 3.7.0

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.6 FATAL_ERROR)
 
 # TODO Remove this deprecated policy switch once we're on cmake 3.4 or later
 cmake_policy(SET CMP0065 OLD)
@@ -26,10 +26,6 @@ option(USE_CLANG_TIDY "build with clang-tidy checks enabled" OFF)
 option(USE_IWYU "build with iwyu checks enabled" OFF)
 option(CLANG_TIDY_WARNINGS_AS_ERRORS "treat clang-tidy warnings as errors" OFF)
 
-if(USE_IWYU)
-    # note: for iwyu, we need cmake 3.3
-    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
-endif()
 if(USE_CLANG_TIDY)
     # note: for clang-tidy, we need cmake 3.6, or (if the return code should be handled correctly, e.g. on CI), we need 3.8.
     cmake_minimum_required(VERSION 3.8 FATAL_ERROR)

ChangeLog.txt

@@ -3,6 +3,9 @@ Version 0.11.0 (unreleased)
 Build changes:
 * Switch to Conan package manager
 
+Other changes:
+* Now requires CMake 3.6 or later
+
 New features:
 * Add support for atime mount options (noatime, strictatime, relatime, atime, nodiratime). As before, relatime is the default.
 

README.md

@@ -13,7 +13,7 @@ This only works for Ubuntu 17.04 and later, and Debian Stretch and later.
 You can also use CryFS on older versions of these distributions by following the **Building from source** instructions below.
 
     sudo apt install cryfs
-    
+
 OSX
 ----
 
@@ -21,7 +21,7 @@ CryFS is distributed via Homebrew. Just do
 
     brew cask install osxfuse
     brew install cryfs
-    
+
 Windows (experimental)
 ----------------------
 
@@ -44,7 +44,7 @@ Requirements
 ------------
   - Git (for getting the source code)
   - GCC version >= 6.5 or Clang >= 4.0
-  - CMake version >= 3.1
+  - CMake version >= 3.6
   - Conan package manager
   - libcurl4 (including development headers)
   - SSL development libraries (including development headers, e.g. libssl-dev)