Build error on OSX 10.12.6

[tomplex]

I'm trying to install this library on OSX. geos & gdal are already installed, but I'm getting a linker error on make:

Undefined symbols for architecture x86_64:
  "_GEOSCoordSeq_create", referenced from:
      exactextract::FloodFill::cell_is_inside(unsigned long, unsigned long) const in floodfill.cpp.o
      exactextract::geos_make_box_polygon(double, double, double, double) in geos_utils.cpp.o
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSCoordSeq_destroy", referenced from:
      exactextract::FloodFill::cell_is_inside(unsigned long, unsigned long) const in floodfill.cpp.o
      exactextract::geos_make_box_polygon(double, double, double, double) in geos_utils.cpp.o
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSCoordSeq_getSize", referenced from:
      exactextract::read(GEOSCoordSeq_t const*) in geos_utils.cpp.o
      exactextract::initial_segment_orientation(GEOSCoordSeq_t const*) in geos_utils.cpp.o
      exactextract::RasterCellIntersection::process_ring(GEOSGeom_t const*, bool) in raster_cell_intersection.cpp.o
  "_GEOSCoordSeq_getX", referenced from:
      exactextract::geos_get_box(GEOSGeom_t const*) in geos_utils.cpp.o
      exactextract::read(GEOSCoordSeq_t const*) in geos_utils.cpp.o
      exactextract::initial_segment_orientation(GEOSCoordSeq_t const*) in geos_utils.cpp.o
      exactextract::RasterCellIntersection::process_ring(GEOSGeom_t const*, bool) in raster_cell_intersection.cpp.o
  "_GEOSCoordSeq_getY", referenced from:
      exactextract::geos_get_box(GEOSGeom_t const*) in geos_utils.cpp.o
      exactextract::read(GEOSCoordSeq_t const*) in geos_utils.cpp.o
      exactextract::initial_segment_orientation(GEOSCoordSeq_t const*) in geos_utils.cpp.o
      exactextract::RasterCellIntersection::process_ring(GEOSGeom_t const*, bool) in raster_cell_intersection.cpp.o
  "_GEOSCoordSeq_setX", referenced from:
      exactextract::FloodFill::cell_is_inside(unsigned long, unsigned long) const in floodfill.cpp.o
      exactextract::geos_make_box_polygon(double, double, double, double) in geos_utils.cpp.o
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSCoordSeq_setY", referenced from:
      exactextract::FloodFill::cell_is_inside(unsigned long, unsigned long) const in floodfill.cpp.o
      exactextract::geos_make_box_polygon(double, double, double, double) in geos_utils.cpp.o
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSEnvelope", referenced from:
      exactextract::geos_get_box(GEOSGeom_t const*) in geos_utils.cpp.o
  "_GEOSGeomGetX", referenced from:
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSGeomGetY", referenced from:
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSGeomTypeId", referenced from:
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
      exactextract::RasterCellIntersection::process(GEOSGeom_t const*) in raster_cell_intersection.cpp.o
  "_GEOSGeom_clone", referenced from:
      exactextract::FloodFill::FloodFill(GEOSGeom_t const*, exactextract::Grid<exactextract::bounded_extent> const&) in floodfill.cpp.o
  "_GEOSGeom_createLineString", referenced from:
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSGeom_createLinearRing", referenced from:
      exactextract::geos_make_box_polygon(double, double, double, double) in geos_utils.cpp.o
  "_GEOSGeom_createPoint", referenced from:
      exactextract::FloodFill::cell_is_inside(unsigned long, unsigned long) const in floodfill.cpp.o
  "_GEOSGeom_createPolygon", referenced from:
      exactextract::FloodFill::FloodFill(GEOSGeom_t const*, exactextract::Grid<exactextract::bounded_extent> const&) in floodfill.cpp.o
      exactextract::geos_make_box_polygon(double, double, double, double) in geos_utils.cpp.o
  "_GEOSGeom_destroy", referenced from:
      exactextract::FloodFill::FloodFill(GEOSGeom_t const*, exactextract::Grid<exactextract::bounded_extent> const&) in floodfill.cpp.o
      exactextract::FloodFill::cell_is_inside(unsigned long, unsigned long) const in floodfill.cpp.o
      exactextract::geos_make_box_polygon(double, double, double, double) in geos_utils.cpp.o
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
      exactextract::geos_get_box(GEOSGeom_t const*) in geos_utils.cpp.o
  "_GEOSGeom_getCoordSeq", referenced from:
      exactextract::geos_get_box(GEOSGeom_t const*) in geos_utils.cpp.o
      exactextract::RasterCellIntersection::process_ring(GEOSGeom_t const*, bool) in raster_cell_intersection.cpp.o
  "_GEOSGetExteriorRing", referenced from:
      exactextract::geos_get_box(GEOSGeom_t const*) in geos_utils.cpp.o
      exactextract::RasterCellIntersection::process(GEOSGeom_t const*) in raster_cell_intersection.cpp.o
  "_GEOSGetGeometryN", referenced from:
      exactextract::RasterCellIntersection::process(GEOSGeom_t const*) in raster_cell_intersection.cpp.o
  "_GEOSGetInteriorRingN", referenced from:
      exactextract::RasterCellIntersection::process(GEOSGeom_t const*) in raster_cell_intersection.cpp.o
  "_GEOSGetNumGeometries", referenced from:
      exactextract::RasterCellIntersection::process(GEOSGeom_t const*) in raster_cell_intersection.cpp.o
  "_GEOSGetNumInteriorRings", referenced from:
      exactextract::RasterCellIntersection::process(GEOSGeom_t const*) in raster_cell_intersection.cpp.o
  "_GEOSIntersection", referenced from:
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
  "_GEOSOrientationIndex", referenced from:
      exactextract::geos_is_ccw(GEOSCoordSeq_t const*) in geos_utils.cpp.o
  "_GEOSPrepare", referenced from:
      exactextract::FloodFill::FloodFill(GEOSGeom_t const*, exactextract::Grid<exactextract::bounded_extent> const&) in floodfill.cpp.o
  "_GEOSPreparedContains", referenced from:
      exactextract::FloodFill::cell_is_inside(unsigned long, unsigned long) const in floodfill.cpp.o
  "_GEOSPreparedGeom_destroy", referenced from:
      exactextract::FloodFill::FloodFill(GEOSGeom_t const*, exactextract::Grid<exactextract::bounded_extent> const&) in floodfill.cpp.o
  "_GEOSisEmpty", referenced from:
      exactextract::segment_intersection(exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate const&, exactextract::Coordinate&) in geos_utils.cpp.o
      exactextract::RasterCellIntersection::RasterCellIntersection(exactextract::Grid<exactextract::bounded_extent> const&, GEOSGeom_t const*) in raster_cell_intersection.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [libexactextract.dylib] Error 1
make[1]: *** [CMakeFiles/exactextract_SHARED.dir/all] Error 2
make: *** [all] Error 2

When running the cmake -DCMAKE_BUILD_TYPE=Release .. command, it is able to find the GEOS and GDAL libraries:

➙ cmake -DCMAKE_BUILD_TYPE=Release ..
-- The C compiler identification is AppleClang 9.0.0.9000039
-- The CXX compiler identification is AppleClang 9.0.0.9000039
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found GEOS: /Library/Frameworks/GEOS.framework
-- Found GDAL: /Library/Frameworks/GDAL.framework/Versions/2.1/unix/lib/libgdal.dylib

Any idea what might be causing this?

[dbaston]

I don't have access to OS X to explore this, but it seems a little suspicious that the cmake output shows a path to a dylib for GDAL but not for GEOS.

[tomplex]

Interesting. I have a libgeos.dylib and libgeos_c.dylib in my /Library/Frameworks/GEOS.framework/Versions/3/unix/lib directory.

[dbaston]

The _c one is what it should be linking against.

[tomplex]

I'm pretty unfamiliar with the guts of this sort of thing, any recommendations as to how to make that happen, or what to search for?

[dbaston]

You could do make exactextract_bin VERBOSE=1 and see what the linker invocation actually looks like, and then try tweaking that command. I'm guessing you'll see that the libgeos_c.dylib file isn't being passed to the linker.

If this is the case, you'd want to poke around in FindGEOS.cmake and see if you can find out why. It's possible that the issue has come up in a large project like QGIS and been fixed there.

[tomplex]

Thanks, Dan. Will dig deeper when I get a chance and let you know how it turns out.

[dbaston]

Fixed by 81f7a42