vcpkg错误分析方法

最近在使用vcpkg时，经常会碰到CMake错误。 有些以前能编译通过的包， 过一段时间又不能编译错误了。 错误提示一般是CMake错误， 弄得很郁闷。

我采用以下步骤解决了问题：

1. 分析错误
2. 查看错误日志
3. 查看cmake文件
4. 手工处理错误

下面是我opencv编译错误解决过程：

1.  执行vcpkg命令

PS D:\Develop\GitOthers\vcpkg> ./vcpkg install opencv

2.  错误信息

CMake Error at scripts/cmake/vcpkg_execute_required_process.cmake:43 (message):
    ......
    See logs for more information:
      D:\Develop\GitOthers\vcpkg\buildtrees\opencv\config-x64-windows-rel-out.log
      D:\Develop\GitOthers\vcpkg\buildtrees\opencv\config-x64-windows-rel-err.log

Call Stack (most recent call first):
  scripts/cmake/vcpkg_configure_cmake.cmake: (vcpkg_execute_required_process)
  ports/opencv/portfile.cmake: (vcpkg_configure_cmake)
  scripts/ports.cmake: (include)

Error: Building package opencv:x64-windows failed with: BUILD_FAILED
Please ensure you're using the latest portfiles with `.\vcpkg update`, then
submit an issue at https://github.com/Microsoft/vcpkg/issues including:
  Package: opencv:x64-windows
  Vcpkg version: 0.0.-fd9b73987bf215f1d10acf4207c3cc637a1bcf2c

Additionally, attach any relevant sections from the log files above.

3. 查看错误日志（XXX-err.log）

CMake Warning at 3rdparty/ippicv/downloader.cmake: (message):
  ICV: Local copy of ICV package has invalid MD5 hash:
  0d1682bf35ca5cd296a7cc795d30ecc8 (expected:
  04e81ce5d0e329c3fbc606ae32cad44d)
Call Stack (most recent call first):
  3rdparty/ippicv/downloader.cmake: (_icv_downloader)
  cmake/OpenCVFindIPP.cmake: (include)
  cmake/OpenCVFindLibsPerf.cmake: (include)
  CMakeLists.txt: (include)

CMake Error at 3rdparty/ippicv/downloader.cmake: (file):
  file DOWNLOAD HASH mismatch

    for file: [D:/Develop/GitOthers/vcpkg/buildtrees/opencv/src/opencv-3.2./3rdparty/ippicv/downloads/windows-04e81ce5d0e329c3fbc606ae32cad44d/ippicv_windows_20151201.zip]
      expected hash: [04e81ce5d0e329c3fbc606ae32cad44d]
        actual hash: [57ed63670f6763ece0d789f9cb52d952]
             status: [;"Timeout was reached"]

Call Stack (most recent call first):
  3rdparty/ippicv/downloader.cmake: (_icv_downloader)
  cmake/OpenCVFindIPP.cmake: (include)
  cmake/OpenCVFindLibsPerf.cmake: (include)
  CMakeLists.txt: (include)

CMake Error at 3rdparty/ippicv/downloader.cmake: (message):
  ICV: Failed to download ICV package: ippicv_windows_20151201.zip.
  Status=;"Timeout was reached"
Call Stack (most recent call first):
  3rdparty/ippicv/downloader.cmake: (_icv_downloader)
  cmake/OpenCVFindIPP.cmake: (include)
  cmake/OpenCVFindLibsPerf.cmake: (include)
  CMakeLists.txt: (include)

查看日志， 发现原来是有个文件下载不完整， 造成了后续操作无法完成。

4. 如何解决问题呢？

查看opencv-3.2.\3rdparty\ippicv\downloader.cmake文件，找到相应的下载文件，手动下载 ippicv_windows_20151201.zip
下载完成后，将文件复制到 D:/Develop/GitOthers/vcpkg/buildtrees/opencv/src/opencv-3.2.0/3rdparty/ippicv/downloads/windows-04e81ce5d0e329c3fbc606ae32cad44d/ippicv_windows_20151201.zip

然后再次执行vcpkg编译命令