CMake Error at CMakeLists.txt: (FIND_PACKAGE)找不到ncnn包的解决方法

问题描述

demo指路：https://github.com/EdVince/Stable-Diffusion-NCNN
在Linux端使用

cmake

编译文件时，

cd x86/linux
mkdir-p build &&cd build
cmake ..make -j$(nproc)

执行

cmake ..

命令，报错：

CMake Error at CMakeLists.txt:14 (FIND_PACKAGE):
  By not providing "Findncnn.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "ncnn", but
  CMake did not find one.

  Could not find a package configuration file provided by "ncnn" with any of
  the following names:

    ncnnConfig.cmake
    ncnn-config.cmake

  Add the installation prefix of "ncnn" to CMAKE_PREFIX_PATH or set
  "ncnn_DIR" to a directory containing one of the above files.  If "ncnn"
  provides a separate development package or SDK, be sure it has been
  installed.

-- Configuring incomplete, errors occurred!
See also "/home/gaoyi/ldm-ncnn/Stable-Diffusion-NCNN/x86/linux/CMakeFiles/CMakeOutput.log".

问题原因

拉取

ncnn

的代码库（包括submodule）后没有

build and Install

，所以

cmake

时找不到对应的包，只需要让它找到对应的包即可，分为2步：

1. 生成对应的cmake文件（ncnnConfig.cmake、ncnn-config.cmake）
2. 设置环境变量（CMAKE_PREFIX_PATH或者ncnn_DIR）

解决方法

1. build and Install ncnn

需要执行以下命令：

cd ncnn
mkdir-p build
cd build
cmake ..

cmake

之后继续在build目录下，执行：

makeinstall

发现弹出的信息中有：

这其中的

ncnnConfig.cmake、ncnn.cmake

就是我们需要找的包，找到上一级目录，右键复制路径

1. 设置环境变量

exportncnn_DIR=/home/gaoyi/ldm-ncnn/Stable-Diffusion-NCNN/ncnn/build/install/lib/cmake/ncnn

这个环境变量就是上一步复制的路径

1. 重新运行cmake

cmake ..

看到：

-- Configuring done
-- Generating done
-- Build files have been written to: /home/gaoyi/ldm-ncnn/Stable-Diffusion-NCNN/x86/linux

成功！