Building on macos required cmake changes due to missing header files

When trying to build with python setup.py build I ran into numerous errors due to not found headers. However the dependencies were already present and installed using brew, e.g. brew install gflags opencv ...

python 3.7.7
cmake version 3.17.2
macos 10.15.4.

Example error:

[ 29%] Building C object third_party/vlfeat/CMakeFiles/vl.dir/vl/kmeans.c.o
/OpenSfM/opensfm/src/third_party/gtest/gmock_main.cc:33:10: fatal error: 'gflags/gflags.h' file not found
#include "gflags/gflags.h"
         ^~~~~~~~~~~~~~~~~
1 error generated.
make[2]: *** [CMakeFiles/gtest.dir/third_party/gtest/gmock_main.cc.o] Error 1

I had to add include_directories(${GLOG_INCLUDE_DIRS} ${GFLAGS_INCLUDE_DIRS}) after the find_packages command to fix the build for my setup.

The complete set of changes which I made.

diff --git opensfm/src/CMakeLists.txt opensfm/src/CMakeLists.txt
index 1d5d881..45eb89e 100644
--- opensfm/src/CMakeLists.txt
+++ opensfm/src/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.0)
+LINK_DIRECTORIES(/usr/local/Cellar)

 project(opensfm C CXX)

@@ -39,6 +39,9 @@ find_package(Eigen REQUIRED)
 find_package(Ceres REQUIRED)
 find_package(Gflags REQUIRED)
 find_package(Glog REQUIRED)
+find_package(gtest REQUIRED)
+
+include_directories(${GLOG_INCLUDE_DIRS} ${GFLAGS_INCLUDE_DIRS})

 find_package(OpenCV)
 # OpenCV's OpenCVConfig will enforce imgcodecs for < 3.0

I'm not familiar with cmake and the particulars of its build system but the include_directories command was found via this stackoverflow answer. Using it and other "whack-a-mole" modifications to the CMakeLists.txt allowed a successful build

mapillary / OpenSfM

Building on macos required cmake changes due to missing header files #592