我在ubuntu上安装exiv2，执行第一步cmake的时候报错
CMake Error at /usr/share/cmake-3.9/Modules/FindPackageHandleStandardArgs.cmake:137 (message):Could NOT find EXPAT (missing: EXPAT_LIBRARY EXPAT_INCLUDE_DIR)
Call Stack (most recent call first):/usr/share/cmake-3.9/Modules/FindPackageHandleStandardArgs.cmake:377 (_FPHSA_FAILURE_MESSAGE)/usr/share/cmake-3.9/Modules/FindEXPAT.cmake:48 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)cmake/findDependencies.cmake:37 (find_package)CMakeLists.txt:62 (include)
这是说明缺少了-devle文件 ，安装libexpat-devel可解决此问题。
对于常见操作系统通过包管理器安装libexpat-devel的命令如下：
| 操作系统 | 包管理器 | 安装命令 |
|---|---|---|
| Debian GNU/Linux \ Ubuntu | apt | sudo apt-get install -y libexpat1 libexpat1-dev |
| macOS | HomeBrew | brew install expat |
| CentOS | yum | sudo yum install -y expat expat-devel |
安装完成后，再次执行cmake命令就顺利执行了。
参考：
how-to-install-geant4-on-linux
Expat