ITKMontage double-conversion problem

I built ITK 5.2, pulled from GitHub, and built ITKMontage and the examples. It did build successfully. Then I tried to run ITKMontage’s example CompleteMontage. The ITKMontage examples come with a CMakeLists.txt. When I tried to build the CompleteMontage example in CLion on Mac BigSur just to see the results, but it didn’t build, giving this error:

In file included from /Users/lambda/ITKMontage/examples/CompareTileConfigurations.cxx:20:
/usr/local/include/ITK-5.2/itkTileConfiguration.h:28:10: fatal error: 'double-conversion/double-conversion.h' file not found
#include "double-conversion/double-conversion.h"
1 error generated.
make[3]: *** [CMakeFiles/CompareTileConfigurations.dir/CompareTileConfigurations.cxx.o] Error 1
make[2]: *** [CMakeFiles/CompareTileConfigurations.dir/all] Error 2
make[1]: *** [CMakeFiles/CompareTileConfigurations.dir/rule] Error 2
make: *** [CompareTileConfigurations] Error 2

Then I tried to build a hello world program but with #include "double-conversion/double-conversion.h", and got the same error. I did put find_package(ITK 5.2 REQUIRED COMPONENTS Montage ITKImageIO ITKTransformIO ITKDoubleConversion) in CMakeLists.txt. It seems that ITK has its own internal version of double-conversion. I installed double-conversion from Google to standard location, and this problem persists.

I’m new to cmake, so maybe I did something dumb. Or are we supposed to run examples directly in the IDE? Please help, thanks!

Something similar has already occurred before:

Does any part of that discussion help you? Which version of double-conversion do you have installed? You don’t need to use it, you could just use the one bundled with ITK.