使用CMake + Ninja下载依赖项

Question

我有一个ExternalProject依赖项，它在构建过程中被克隆(使用git)。对于CMake + Make，这一切都很好。

mkdir build && cd build; 
cmake ..
make

当我键入make时，它将正确地克隆和构建使用git的库。

但是，当我使用忍者生成器时：

mkdir build && cd build; 
cmake -GNinja ..
ninja

我得到以下错误：

$ cmake -GNinja ..                                                                                                                                                                                                                                                   -- The C compiler identification is AppleClang 6.0.0.6000054
-- The CXX compiler identification is AppleClang 6.0.0.6000054
-- Check for working C compiler using: Ninja
-- Check for working C compiler using: Ninja -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler using: Ninja
-- Check for working CXX compiler using: Ninja -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Boost version: 1.56.0
-- Found the following Boost libraries:
--   unit_test_framework
-- Found Git: /usr/local/bin/git (found version "2.1.2")
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/carneiro/src/gamgee/build

$ ninja
ninja: error: 'contrib/htslib-prefix/src/htslib/libhts.a', needed by 'test/gamgee_test', missing and no known rule to make it


Is git downloading of external projects not supported by the cmake+ninja combo?

Answer 1

事实证明，如果您在构建之前进行了清理，则所有这些操作都会正常工作，而忍者确实正确地下载了我的依赖项。

工作流程如下所示：

mkdir build && cd build
cmake -G Ninja ..
ninja clean  # if you don't do this, it will not download Externalproject dependencies
ninja

一定是Ninja生成器中的某种bug，但我现在对这个工作流很满意。