我尝试在Ubuntu 18.04中安装SAGA-GIS，但未成功。我正在阅读几篇文章，首先我做了：
sudo add-apt-repository ppa:johanvdw/saga-gis
sudo apt-get update
sudo apt-get install saga
sudo apt-get install saga
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
saga : Depends: gdal-abi-2-3-0
Depends: libgdal20 (>= 2.3.0) but it is not going to be installed
Depends: libopencv-calib3d3.2 but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
没有用，比我尝试的要
sudo apt-get install saga -f
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
saga : Depends: gdal-abi-2-3-0
Depends: libgdal20 (>= 2.3.0) but it is not going to be installed
Depends: libopencv-calib3d3.2 but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
如果我尝试安装依赖项：
sudo apt-get install gdal-abi-2-3-0 libgdal20 libopencv-calib3d3.2
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package gdal-abi-2-3-0 is a virtual package provided by:
libgdal20 2.3.2+dfsg-2 [Not candidate version]
E: Package 'gdal-abi-2-3-0' has no installation candidate
也不起作用！有任何想法吗？谢谢