Add support for Boost_NO_BOOST_CMAKE=ON for Boost::python

plugin/al/CMakeLists.txt

@@ -25,7 +25,6 @@ option(SKIP_USDMAYA_TESTS "Build tests" OFF)
 # Adding specific components forces calls to _Boost_find_library, which
 # is the rationale for listing them here.
 set(Boost_FIND_COMPONENTS
-     python
      thread
 )
 if(NEED_BOOST_FILESYSTEM)
@@ -44,6 +43,35 @@ if(WIN32)
     endif()
 endif()
 
+find_package(Boost REQUIRED)
+
+# As of boost 1.67 the boost_python component name includes the
+# associated Python version (e.g. python27, python36). After boost 1.70
+# the built-in cmake files will deal with this. If we are using boost
+# that does not have working cmake files, or we are using a new boost
+# and not using cmake's boost files, we need to do the below.
+# https://cmake.org/cmake/help/latest/module/FindBoost.html
+# Find the component under the versioned name and then set the generic
+# Boost_PYTHON_LIBRARY variable so that we don't have to duplicate this
+# logic in each library's CMakeLists.txt.
+set(boost_version_string "${Boost_MAJOR_VERSION}.${Boost_MINOR_VERSION}.${Boost_SUBMINOR_VERSION}")
+if (((${boost_version_string} VERSION_GREATER_EQUAL "1.67") AND
+    (${boost_version_string} VERSION_LESS "1.70")) OR
+    ((${boost_version_string} VERSION_GREATER_EQUAL "1.70") AND
+    Boost_NO_BOOST_CMAKE))
+
+    set(python_version_nodot "${PYTHON_VERSION_MAJOR}${PYTHON_VERSION_MINOR}")
+    list(APPEND Boost_FIND_COMPONENTS
+        python${python_version_nodot}
+    )
+
+    set(Boost_PYTHON_LIBRARY "${Boost_PYTHON${python_version_nodot}_LIBRARY}")
+else()
+    list(APPEND Boost_FIND_COMPONENTS
+        python
+    )
+endif()
+
 find_package(Boost COMPONENTS
                 ${Boost_FIND_COMPONENTS}
                 REQUIRED

plugin/al/lib/AL_USDMaya/CMakeLists.txt

@@ -208,7 +208,7 @@ target_link_libraries(${LIBRARY_NAME}
     usdImaging
     usdImagingGL
     vt
-    Boost::python
+    ${Boost_PYTHON_LIBRARY}
     $<IF:$<VERSION_GREATER_EQUAL:${Boost_VERSION},${boost_1_70_0_ver_string}>,Boost::thread,${Boost_THREAD_LIBRARY}>
     $<$<BOOL:${IS_WINDOWS}>:Boost::chrono>
     $<$<BOOL:${IS_WINDOWS}>:Boost::date_time>

plugin/al/schemas/AL/usd/schemas/maya/tests/CMakeLists.txt

@@ -29,7 +29,7 @@ target_link_libraries(${TARGET_NAME}
     tf
     vt
     plug
-    Boost::python
+    ${Boost_PYTHON_LIBRARY}
 )
 
 # install

plugin/al/usdmayautils/AL/usdmaya/utils/CMakeLists.txt

@@ -63,7 +63,7 @@ target_link_libraries(${USDMAYA_UTILS_LIBRARY_NAME}
   usdGeom
   usdUtils
   vt
-  Boost::python
+  ${Boost_PYTHON_LIBRARY}
   ${PYTHON_LIBRARIES}
   ${MAYA_Foundation_LIBRARY}
   ${MAYA_OpenMaya_LIBRARY}