Remove exact eigen requirement

recipe/meta.yaml

@@ -7,12 +7,13 @@ package:
 source:
   url: http://ceres-solver.org/ceres-solver-{{ version }}.tar.gz
   sha256: 10298a1d75ca884aa0507d1abb0e0f04800a92871cd400d4c361b56a777a7603
+  patches:
+    - remove-exact-eigen-requirement.patch
 
 build:
-  number: 4
+  number: 5
   run_exports:
     - {{ pin_subpackage('ceres-solver', max_pin='x.x') }}
-    - {{ pin_compatible('eigen', max_pin='x.x.x') }}
 
 requirements:
   build:

recipe/remove-exact-eigen-requirement.patch

@@ -0,0 +1,22 @@
+diff --git a/cmake/CeresConfig.cmake.in b/cmake/CeresConfig.cmake.in
+index e5e2976..184d4eb 100644
+--- a/cmake/CeresConfig.cmake.in
++++ b/cmake/CeresConfig.cmake.in
+@@ -193,17 +193,6 @@ set(CERES_EIGEN_VERSION @EIGEN3_VERSION_STRING@)
+ # match and reject with an explanation below.
+ find_package(Eigen3 ${CERES_EIGEN_VERSION} QUIET)
+ if (EIGEN3_FOUND)
+-  if (NOT EIGEN3_VERSION_STRING VERSION_EQUAL CERES_EIGEN_VERSION)
+-    # CMake's VERSION check in FIND_PACKAGE() will accept any version >= the
+-    # specified version. However, only version = is supported. Improve
+-    # usability by explaining why we don't accept non-exact version matching.
+-    ceres_report_not_found("Found Eigen dependency, but the version of Eigen "
+-      "found (${EIGEN3_VERSION_STRING}) does not exactly match the version of Eigen "
+-      "Ceres was compiled with (${CERES_EIGEN_VERSION}). This can cause subtle "
+-      "bugs by triggering violations of the One Definition Rule. See the "
+-      "Wikipedia article http://en.wikipedia.org/wiki/One_Definition_Rule "
+-      "for more details")
+-  endif ()
+   ceres_message(STATUS "Found required Ceres dependency: "
+     "Eigen version ${CERES_EIGEN_VERSION} in ${EIGEN3_INCLUDE_DIRS}")
+ else (EIGEN3_FOUND)