CMake does not find the source directory (installing Eigen) -

I was installing the library on Ubuntu, I followed the instructions by creating a "build directory" with downloaded source directory. That is, I have two directories: eigen-eigen-1306d75b4a21 for the source and an empty eigen-build for the build.

Then I did:

  install cd eigen-build cmake ../eigen-eigen-1306d75b4a21/ sudo  

< An error occurred immediately after installing code> and it closes the installation:

  Threshold error: source directory "/ home / user name / something / eigen-eigen -1306d75b4a21 "does not exist  

Obviously the directory exists. What's wrong with my limit? (I do not know much about seamke. I saw some warnings during the second step, saying that a lot of things like QT4 are missing, but I do not think the reason is because the error message suggests. )