/usr/bin/ld: cannot find -lEigen3::Eigen

[Xue21]

chmod +x build.sh ./build.sh Then it is wrong as below. Configuring and building Thirdparty/DBoW2 ... mkdir: cannot create directory ‘build’: File exists -- Configuring done -- Generating done -- Build files have been written to: /home/ubutu18/ORB_SLAM2/Thirdparty/DBoW2/build [100%] Built target DBoW2 Configuring and building Thirdparty/g2o ... mkdir: cannot create directory ‘build’: File exists -- BUILD TYPE:Release -- Compiling on Unix CMake Warning (dev) at /usr/share/cmake-3.10/Modules/FindOpenMP.cmake:310 (if): if given arguments:

"TRUE"

An argument named "TRUE" appears in a conditional statement. Policy CMP0012 is not set: if() recognizes numbers and boolean constants. Run "cmake --help-policy CMP0012" for policy details. Use the cmake_policy command to set the policy and suppress this warning. Call Stack (most recent call first): /usr/share/cmake-3.10/Modules/FindOpenMP.cmake:425 (_OPENMP_GET_SPEC_DATE) CMakeLists.txt:47 (FIND_PACKAGE) This warning is for project developers. Use -Wno-dev to suppress it.

CMake Warning (dev) at /usr/share/cmake-3.10/Modules/FindOpenMP.cmake:310 (if): if given arguments:

"TRUE"

An argument named "TRUE" appears in a conditional statement. Policy CMP0012 is not set: if() recognizes numbers and boolean constants. Run "cmake --help-policy CMP0012" for policy details. Use the cmake_policy command to set the policy and suppress this warning. Call Stack (most recent call first): /usr/share/cmake-3.10/Modules/FindOpenMP.cmake:425 (_OPENMP_GET_SPEC_DATE) CMakeLists.txt:47 (FIND_PACKAGE) This warning is for project developers. Use -Wno-dev to suppress it.

-- Configuring done -- Generating done -- Build files have been written to: /home/ubutu18/ORB_SLAM2/Thirdparty/g2o/build [100%] Built target g2o Uncompress vocabulary ... Configuring and building ORB_SLAM2 ... mkdir: cannot create directory ‘build’: File exists Build type: Release -- Using flag -std=c++11. CMake Error at CMakeLists.txt:40 (find_package): Found package configuration file:

/home/ubutu18/Pangolin/build/PangolinConfig.cmake

but it set Pangolin_FOUND to FALSE so package "Pangolin" is considered to be NOT FOUND. Reason given by package:

Pangolin could not be found because dependency Eigen3 could not be found.

-- Configuring incomplete, errors occurred! See also "/home/ubutu18/ORB_SLAM2/build/CMakeFiles/CMakeOutput.log". See also "/home/ubutu18/ORB_SLAM2/build/CMakeFiles/CMakeError.log". [ 3%] Linking CXX shared library ../lib/libORB_SLAM2.so /usr/bin/ld: cannot find -lEigen3::Eigen collect2: error: ld returned 1 exit status CMakeFiles/ORB_SLAM2.dir/build.make:624: recipe for target '../lib/libORB_SLAM2.so' failed make[2]: [../lib/libORB_SLAM2.so] Error 1 CMakeFiles/Makefile2:252: recipe for target 'CMakeFiles/ORB_SLAM2.dir/all' failed make[1]: [CMakeFiles/ORB_SLAM2.dir/all] Error 2 Makefile:83: recipe for target 'all' failed make: *** [all] Error 2

[bigorange18]

please install pangolin

[Hello-Water]

if you have installed the "Prerequisites", please delete the document "FindEigen3.cmake" in "cmake_modules" and add your path where eigen3 installed, i.e., "/usr/include/eigen3" Or replace the document "FindEigen3.cmake" with your own file "FindEigen3.cmake".

[9a3eedi]

Thank you @Hello-Water and @gitbug1949 , I was finally able to build ORB-SLAMv2 on Ubuntu 18.04.

What I did is install eigen from the package manager, install pangolin after building it from source (i.e. sudo make install), then I deleted FindEigen3.cmake, and in the CMakeLists.txt, I added "/usr/include/eigen3" to the include_directories() lines

[IHKYoung]

just remove cmake_modules