fatal error: 'google/sparse_hash_map' file not found

[shreeshl]

I have installed sparsehash without any troubles. While trying to build fast_align getting the following error:

error:/Users/shreesh/Project/fast_align-master/src/hashtables.h:5:10: fatal error: 'google/sparse_hash_map' file
      not found
#include <google/sparse_hash_map>
         ^~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
make[2]: *** [CMakeFiles/fast_align.dir/src/fast_align.cc.o] Error 1
make[1]: *** [CMakeFiles/fast_align.dir/all] Error 2
make: *** [all] Error 2

I tried manually changing the paths in hashtables.h but still couldn't get it to work.

[mcavdar]

Missed sparsehash library in the path.

Set CMAKE_CXX_FLAGS option(in CMakeLists) to:
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11 -O3 -g -I/usr/local/include")
instead of:
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11 -O3 -g")

[Ejaprgmalr]

Meet the same problem, tried to set the CMAKE_CXX_FLAGS as above. But it doesn't work for me.

[aj7tesh]

not working for me too? any update?

[JIE-CHI]

fixed the issue as @mcavdar suggested.
Set CMAKE_CXX_FLAGS option to
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11 -O3 -g -I/usr/local/include", where /usr/local/include should be the path where the SparseHash was found from the output of cmake ../ command.
Clear the cache by deleting the build directory, then start again.

[raphaelmerx]

Meet the same problem, tried to set the CMAKE_CXX_FLAGS as above. But it doesn't work for me.

On macOS sparsehash might be on another path, e.g. set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -std=c++11 -O3 -g -I/opt/homebrew/include")