mxnet: convert to CMakePackage (#21385)

* mxnet: convert to CMakePackage

* Package isn't installed yet, can't find libs

* Fix bug with GCC 8+ and CUDA 10 on PowerPC

* Add space

* Add patch to fix cmake cuda flags

* Space no longer needed

* Add patch to fix OpenBLAS linking

* Add missing CMake flag

* Fix env set, default to Distribution

* Add new version, patch

8 files changed, 155 insertions, 243 deletions

diff --git a/var/spack/repos/builtin/packages/mxnet/cmake_cuda_flags.patch b/var/spack/repos/builtin/packages/mxnet/cmake_cuda_flags.patch
new file mode 100644
index 0000000000..8019f7d423
--- /dev/null
+++ b/var/spack/repos/builtin/packages/mxnet/cmake_cuda_flags.patch
@@ -0,0 +1,14 @@
+https://github.com/apache/incubator-mxnet/pull/17645
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 437d01668..1049a53b2 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -662,7 +662,7 @@ add_subdirectory("3rdparty/mshadow")
+ 
+ set(MXNET_INSTALL_TARGETS mxnet)
+ if(UNIX)
+-  string(APPEND CMAKE_CUDA_FLAGS "${CUDA_ARCH_FLAGS_SPACES}")
++  string(APPEND CMAKE_CUDA_FLAGS " ${CUDA_ARCH_FLAGS_SPACES}")
+   # Create dummy file since we want an empty shared library before linking
+   set(DUMMY_SOURCE ${CMAKE_BINARY_DIR}/dummy.c)
+   file(WRITE ${DUMMY_SOURCE} "")
diff --git a/var/spack/repos/builtin/packages/mxnet/makefile-cuda-stub-1.6.patch b/var/spack/repos/builtin/packages/mxnet/makefile-cuda-stub-1.6.patch
deleted file mode 100644
index fd93a244a9..0000000000
--- a/var/spack/repos/builtin/packages/mxnet/makefile-cuda-stub-1.6.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/Makefile b/Makefile
-index 4746cc434..335c79b64 100644
---- a/Makefile
-+++ b/Makefile
-@@ -518,7 +518,7 @@ ifeq ($(USE_CUDA), 1)
- 	endif
- 	# Make sure to add stubs as fallback in order to be able to build
- 	# without full CUDA install (especially if run without nvidia-docker)
--	LDFLAGS += -L/usr/local/cuda/lib64/stubs
-+	LDFLAGS += -L$(USE_CUDA_PATH)/lib64/stubs
- 	ifeq ($(USE_NCCL), 1)
- 		ifneq ($(USE_NCCL_PATH), NONE)
- 			CFLAGS += -I$(USE_NCCL_PATH)/include
diff --git a/var/spack/repos/builtin/packages/mxnet/makefile-cudnn-path-1.6.patch b/var/spack/repos/builtin/packages/mxnet/makefile-cudnn-path-1.6.patch
deleted file mode 100644
index 8ae19440ad..0000000000
--- a/var/spack/repos/builtin/packages/mxnet/makefile-cudnn-path-1.6.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/Makefile b/Makefile
-index 4746cc434..e738fc53f 100644
---- a/Makefile
-+++ b/Makefile
-@@ -509,7 +509,7 @@ LIB_DEP += $(DMLC_CORE)/libdmlc.a $(NNVM_PATH)/lib/libnnvm.a
- ALL_DEP = $(OBJ) $(EXTRA_OBJ) $(PLUGIN_OBJ) $(LIB_DEP)
- 
- ifeq ($(USE_CUDA), 1)
--	CFLAGS += -I$(ROOTDIR)/3rdparty/nvidia_cub
-+	CFLAGS += -I$(CUB_INCLUDE) -I$(CUDNN_PATH)/include
- 	ALL_DEP += $(CUOBJ) $(EXTRA_CUOBJ) $(PLUGIN_CUOBJ)
- 	LDFLAGS += -lcufft
- 	ifeq ($(ENABLE_CUDA_RTC), 1)
diff --git a/var/spack/repos/builtin/packages/mxnet/makefile.opencv.patch b/var/spack/repos/builtin/packages/mxnet/makefile.opencv.patch
deleted file mode 100644
index 45e04ea626..0000000000
--- a/var/spack/repos/builtin/packages/mxnet/makefile.opencv.patch
+++ /dev/null
@@ -1,35 +0,0 @@
-commit 638527ffaa35ffb0bf88a32910b809df09432406
-Author: Toyohisa Kameyama <kameyama@riken.jp>
-Date:   Mon May 18 11:58:00 2020 +0900
-
-    Makefile bug fix for opencv4.
-
-diff --git a/Makefile b/Makefile
-index 51930c782..7f5d4da39 100644
---- a/Makefile
-+++ b/Makefile
-@@ -165,7 +165,23 @@ endif
- ifeq ($(USE_OPENCV), 1)
- 	CFLAGS += -DMXNET_USE_OPENCV=1
- 	ifneq ($(filter-out NONE, $(USE_OPENCV_INC_PATH)),)
--		CFLAGS += -I$(USE_OPENCV_INC_PATH)/include
-+                ifneq ($(wildcard $(USE_OPENCV_INC_PATH)/include/opencv4/opencv2/opencv*),)
-+                    opencv_inc = -I$(USE_OPENCV_INC_PATH)/include/opencv4
-+                endif
-+                ifneq ($(wildcard $(USE_OPENCV_INC_PATH)/include/opencv2/opencv*),)
-+                    opencv_inc = -I$(USE_OPENCV_INC_PATH)/include
-+                endif
-+                ifneq ($(wildcard $(USE_OPENCV_INC_PATH)/opencv4/opencv2/opencv*),)
-+                    opencv_inc = -I$(USE_OPENCV_INC_PATH)/opencv4
-+                endif
-+                ifneq ($(wildcard $(USE_OPENCV_INC_PATH)/opencv2/opencv*),)
-+                    opencv_inc = -I$(USE_OPENCV_INC_PATH)
-+                endif
-+                ifneq ($(filter-out NONE, $(opencv_inc)),)
-+                    CFLAGS += $(opencv_inc)
-+                else
-+$(error Cannot determine OpenCV include path)
-+                endif
- 		ifeq ($(filter-out NONE, $(USE_OPENCV_LIB_PATH)),)
- $(error Please add the path of OpenCV shared library path into `USE_OPENCV_LIB_PATH`, when `USE_OPENCV_INC_PATH` is not NONE)
- 		endif
diff --git a/var/spack/repos/builtin/packages/mxnet/makefile.patch b/var/spack/repos/builtin/packages/mxnet/makefile.patch
deleted file mode 100644
index ceebe21447..0000000000
--- a/var/spack/repos/builtin/packages/mxnet/makefile.patch
+++ /dev/null
@@ -1,81 +0,0 @@
-From 22b64127d7acc9c255b007e120e2a721f4e136d2 Mon Sep 17 00:00:00 2001
-From: Jianwen WEI <weijianwen@gmail.com>
-Date: Fri, 18 Aug 2017 23:32:16 +0800
-Subject: [PATCH] Enable customize CUB MSHADOW PSLITE CUDA paths.
-
----
- Makefile | 26 +++++++++++++++++++++-----
- 1 file changed, 21 insertions(+), 5 deletions(-)
-
-diff --git a/Makefile b/Makefile
-index c71cb13..a53d072 100644
---- a/Makefile
-+++ b/Makefile
-@@ -14,6 +14,19 @@ ifndef DMLC_CORE
- 	DMLC_CORE = $(ROOTDIR)/dmlc-core
- endif
- 
-+ifndef MSHADOW_PATH
-+	MSHADOW_PATH = $(ROOTDIR)/mshadow
-+endif
-+ifneq ("$(wildcard $(MSHADOW_PATH)/include/mshadow/base.h)","")
-+MSHADOW_INC = $(MSHADOW_PATH)/include
-+else
-+MSHADOW_INC = $(MSHADOW_PATH)
-+endif
-+
-+ifndef PS_PATH
-+	PS_PATH = $(ROOTDIR)/ps-lite
-+endif
-+
- ifndef NNVM_PATH
- 	NNVM_PATH = $(ROOTDIR)/nnvm
- endif
-@@ -32,7 +45,7 @@ ifeq ($(USE_MKL2017), 1)
- 	export USE_MKLML = $(lastword $(RETURN_STRING))
- endif
- 
--include mshadow/make/mshadow.mk
-+include $(MSHADOW_PATH)/make/mshadow.mk
- include $(DMLC_CORE)/make/dmlc.mk
- 
- # all tge possible warning tread
-@@ -49,7 +62,7 @@ ifeq ($(DEBUG), 1)
- else
- 	CFLAGS += -O3 -DNDEBUG=1
- endif
--CFLAGS += -I$(ROOTDIR)/mshadow/ -I$(ROOTDIR)/dmlc-core/include -fPIC -I$(NNVM_PATH)/include -Iinclude $(MSHADOW_CFLAGS)
-+CFLAGS += -I$(MSHADOW_INC) -I$(DMLC_CORE)/include -fPIC -I$(NNVM_PATH)/include -Iinclude $(MSHADOW_CFLAGS)
- LDFLAGS = -pthread $(MSHADOW_LDFLAGS) $(DMLC_LDFLAGS)
- ifeq ($(DEBUG), 1)
- 	NVCCFLAGS = -std=c++11 -Xcompiler -D_FORCE_INLINES -g -G -O0 -ccbin $(CXX) $(MSHADOW_NVCCFLAGS)
-@@ -125,8 +138,11 @@ ifneq ($(USE_CUDA_PATH), NONE)
- 	NVCC=$(USE_CUDA_PATH)/bin/nvcc
- endif
- 
-+ifndef CUB_INCLUDE
-+	CUB_PATH = $(ROOTDIR)/cub
-+endif
-+
- # ps-lite
--PS_PATH=$(ROOTDIR)/ps-lite
- DEPS_PATH=$(shell pwd)/deps
- include $(PS_PATH)/make/ps.mk
- ifeq ($(USE_DIST_KVSTORE), 1)
-@@ -181,11 +197,11 @@ else
- endif
- 
- # all dep
--LIB_DEP += $(DMLC_CORE)/libdmlc.a $(NNVM_PATH)/lib/libnnvm.a
-+LIB_DEP += $(DMLC_CORE)/lib/libdmlc.a $(NNVM_PATH)/lib/libnnvm.a
- ALL_DEP = $(OBJ) $(EXTRA_OBJ) $(PLUGIN_OBJ) $(LIB_DEP)
- 
- ifeq ($(USE_CUDA), 1)
--	CFLAGS += -I$(ROOTDIR)/cub
-+	CFLAGS += -I$(CUB_INCLUDE) -I$(USE_CUDA_PATH)/include -I$(CUDNN_PATH)/include
- 	ALL_DEP += $(CUOBJ) $(EXTRA_CUOBJ) $(PLUGIN_CUOBJ)
- 	LDFLAGS += -lcuda -lcufft
- 	SCALA_PKG_PROFILE := $(SCALA_PKG_PROFILE)-gpu
--- 
-1.8.3.1
-
diff --git a/var/spack/repos/builtin/packages/mxnet/openblas-1.6.0.patch b/var/spack/repos/builtin/packages/mxnet/openblas-1.6.0.patch
new file mode 100644
index 0000000000..157b857c81
--- /dev/null
+++ b/var/spack/repos/builtin/packages/mxnet/openblas-1.6.0.patch
@@ -0,0 +1,14 @@
+https://github.com/apache/incubator-mxnet/pull/19174
+--- a/CMakeLists.txt	2020-01-30 17:45:22.000000000 -0600
++++ b/CMakeLists.txt	2021-02-03 11:11:30.000000000 -0600
+@@ -446,7 +446,9 @@
+ if(USE_LAPACK)
+   message("USE_LAPACK is ON")
+   add_definitions(-DMXNET_USE_LAPACK=1)
+-  if (NOT MSVC)
++  # BLAS=open case is handled in ChooseBlas.cmake
++  if(NOT MSVC AND NOT CMAKE_BUILD_TYPE STREQUAL "Distribution"
++     AND NOT BLAS STREQUAL "Open" AND NOT BLAS STREQUAL "open")
+     list(APPEND mxnet_LINKER_LIBS lapack)
+   endif()
+ endif()
diff --git a/var/spack/repos/builtin/packages/mxnet/openblas-1.7.0.patch b/var/spack/repos/builtin/packages/mxnet/openblas-1.7.0.patch
new file mode 100644
index 0000000000..e143671a08
--- /dev/null
+++ b/var/spack/repos/builtin/packages/mxnet/openblas-1.7.0.patch
@@ -0,0 +1,16 @@
+https://github.com/apache/incubator-mxnet/pull/19174
+--- a/CMakeLists.txt	2020-07-16 00:32:00.000000000 -0500
++++ b/CMakeLists.txt	2021-02-02 15:30:13.000000000 -0600
+@@ -446,9 +446,9 @@
+ if(USE_LAPACK)
+   message("USE_LAPACK is ON")
+   add_definitions(-DMXNET_USE_LAPACK=1)
+-  # In the CMAKE_BUILD_TYPE="Distribution" case, we link against Blas libraries
+-  # that already provide lapack symbols. Thus -llapack would be wrong.
+-  if (NOT MSVC AND NOT CMAKE_BUILD_TYPE STREQUAL "Distribution")
++  # BLAS=open case is handled in ChooseBlas.cmake
++  if(NOT MSVC AND NOT CMAKE_BUILD_TYPE STREQUAL "Distribution"
++     AND NOT BLAS STREQUAL "Open" AND NOT BLAS STREQUAL "open")
+     list(APPEND mxnet_LINKER_LIBS lapack)
+   endif()
+ endif()
diff --git a/var/spack/repos/builtin/packages/mxnet/package.py b/var/spack/repos/builtin/packages/mxnet/package.py
index 2a5e652120..87121cb5c2 100644
--- a/var/spack/repos/builtin/packages/mxnet/package.py
+++ b/var/spack/repos/builtin/packages/mxnet/package.py
@@ -6,129 +6,139 @@
 from spack import *
 
 
-class Mxnet(MakefilePackage, CudaPackage):
+class Mxnet(CMakePackage, CudaPackage):
     """MXNet is a deep learning framework
     designed for both efficiency and flexibility."""
 
-    homepage = "http://mxnet.io"
-    url      = "https://github.com/apache/incubator-mxnet/releases/download/1.3.0/apache-mxnet-src-1.3.0-incubating.tar.gz"
+    homepage = "https://mxnet.apache.org"
+    url      = "https://archive.apache.org/dist/incubator/mxnet/1.7.0/apache-mxnet-src-1.7.0-incubating.tar.gz"
+    list_url = "https://mxnet.apache.org/get_started/download"
+    git      = "https://github.com/apache/incubator-mxnet.git"
 
     maintainers = ['adamjstewart']
-
+    import_modules = [
+        'mxnet', 'mxnet.numpy_extension', 'mxnet.optimizer', 'mxnet.module',
+        'mxnet.io', 'mxnet.cython', 'mxnet.ndarray', 'mxnet.gluon',
+        'mxnet.symbol', 'mxnet._cy3', 'mxnet.contrib', 'mxnet.numpy',
+        'mxnet._ffi', 'mxnet.image', 'mxnet.kvstore', 'mxnet.notebook',
+        'mxnet._ctypes', 'mxnet.rnn', 'mxnet.ndarray.numpy_extension',
+        'mxnet.ndarray.numpy', 'mxnet.gluon.nn', 'mxnet.gluon.model_zoo',
+        'mxnet.gluon.contrib', 'mxnet.gluon.data', 'mxnet.gluon.rnn',
+        'mxnet.gluon.model_zoo.vision', 'mxnet.gluon.contrib.nn',
+        'mxnet.gluon.contrib.estimator', 'mxnet.gluon.contrib.cnn',
+        'mxnet.gluon.contrib.data', 'mxnet.gluon.contrib.rnn',
+        'mxnet.gluon.data.vision', 'mxnet.symbol.numpy_extension',
+        'mxnet.symbol.numpy', 'mxnet.contrib.onnx',
+        'mxnet.contrib.svrg_optimization', 'mxnet.contrib.amp',
+        'mxnet.contrib.text', 'mxnet.contrib.onnx.mx2onnx',
+        'mxnet.contrib.onnx.onnx2mx', 'mxnet.contrib.amp.lists',
+        'mxnet._ffi._cy3', 'mxnet._ffi._ctypes'
+    ]
+
+    version('master', branch='master')
+    version('1.master', branch='v1.x')
+    version('1.7.0', sha256='1d20c9be7d16ccb4e830e9ee3406796efaf96b0d93414d676337b64bc59ced18')
     version('1.6.0', sha256='01eb06069c90f33469c7354946261b0a94824bbaf819fd5d5a7318e8ee596def')
     version('1.3.0', sha256='c00d6fbb2947144ce36c835308e603f002c1eb90a9f4c5a62f4d398154eed4d2')
 
+    variant('build_type', default='Distribution',
+            description='CMake build type',
+            values=('Distribution', 'Debug', 'Release',
+                    'RelWithDebInfo', 'MinSizeRel'))
     variant('cuda', default=True, description='Enable CUDA support')
+    variant('cudnn', default=True, description='Build with cudnn support')
+    variant('nccl', default=False, description='Use NVidia NCCL with CUDA')
     variant('opencv', default=True, description='Enable OpenCV support')
     variant('openmp', default=False, description='Enable OpenMP support')
-    variant('profiler', default=False, description='Enable Profiler (for verification and debug only).')
+    variant('lapack', default=True, description='Build with lapack support')
+    variant('mkldnn', default=False, description='Build with MKL-DNN support')
     variant('python', default=True, description='Install python bindings')
 
-    depends_on('dmlc-core@20170508')
-    depends_on('dmlc-core+openmp', when='+openmp')
-    depends_on('dmlc-core~openmp', when='~openmp')
-    depends_on('mshadow@20170721')
-    depends_on('ps-lite@20170328')
-    depends_on('nnvm~shared@20170418')
+    depends_on('cmake@3.13:', type='build')
+    depends_on('ninja', type='build')
+    depends_on('pkgconfig', when='@1.6.0', type='build')
     depends_on('blas')
-    depends_on('cudnn', when='+cuda')
-    depends_on('cudnn', when='+cuda')
-    depends_on('cub', when='+cuda')
-    depends_on('opencv+core+imgproc+highgui+jpeg+png+tiff~eigen~ipp@3.0:3.4.99', when='@1.3.0 +opencv')
-    depends_on('opencv+core+imgproc+highgui+jpeg+png+tiff~eigen~ipp@3.0:', when='+opencv')
-
-    # python extensions
-    depends_on('python@2.7:', type=('build', 'run'), when='+python')
-    depends_on('py-setuptools', type='build', when='+python')
-    depends_on('py-numpy@:1.15.0', type=('build', 'run'), when='@1.3.0 +python')
-    depends_on('py-numpy@1.16:', type=('build', 'run'), when='@1.6.0 +python')
-    extends('python', when='+python')
+    depends_on('cudnn', when='+cudnn')
+    depends_on('nccl', when='+nccl')
+    depends_on('opencv+core+highgui+imgproc+imgcodecs', when='+opencv')
+    depends_on('lapack', when='+lapack')
+    depends_on('onednn', when='+mkldnn')
 
-    patch('makefile.opencv.patch', when='@1.6.0')
-    patch('makefile-cudnn-path-1.6.patch', when='@1.6.0')
-    patch('makefile-cuda-stub-1.6.patch', when='@1.6.0')
+    # python/setup.py
+    extends('python', when='+python')
+    depends_on('python@2.7:2.8,3.4:', when='+python', type=('build', 'run'))
+    depends_on('py-setuptools', when='+python', type='build')
+    depends_on('py-cython', when='+python', type='build')
+    depends_on('py-numpy@1.16.1:1.999', when='@1.6:+python', type=('build', 'run'))
+    depends_on('py-numpy@1.8.2:1.15.0', when='@1.3.0+python', type=('build', 'run'))
+    depends_on('py-requests@2.20.0:2.999', when='@1.6:+python', type=('build', 'run'))
+    depends_on('py-requests@2.18.4:2.18.999', when='@1.3.0+python', type=('build', 'run'))
+    depends_on('py-graphviz@0.8.1:0.8.999', when='+python', type=('build', 'run'))
+
+    conflicts('+cudnn', when='~cuda')
+    conflicts('+nccl', when='~cuda')
+
+    patch('openblas-1.7.0.patch', when='@1.7.0:1.master')
+    patch('openblas-1.6.0.patch', when='@1.6.0')
+    patch('cmake_cuda_flags.patch', when='@1.6:1.7')
     patch('parallell_shuffle.patch', when='@1.6.0')
 
-    def build(self, spec, prefix):
-        # copy template configuration file
-        copy('make/config.mk', 'config.mk')
+    # python/setup.py assumes libs can be found in build directory
+    build_directory = 'build'
+    generator = 'Ninja'
 
-        # remove compiler overrides
-        filter_file('export CC = gcc', '', 'config.mk', string=True)
-        filter_file('export CXX = g++', '', 'config.mk', string=True)
+    def setup_run_environment(self, env):
+        env.set('MXNET_LIBRARY_PATH', self.spec['mxnet'].libs[0])
 
-        # add blas prefix to include paths
-        filter_file(
-            '-I$(NNVM_PATH)/include',
-            '-I$(NNVM_PATH)/include -I%s/include' % spec['blas'].prefix,
-            'Makefile', string=True
-        )
-
-        # mxnet comes with its own version of nnvm and dmlc.
-        # building it will fail if we use the spack paths
+        if self.spec.satisfies('+nccl ^nccl@2.1:'):
+            env.set('NCCL_LAUNCH_MODE', 'PARALLEL')
 
+    def cmake_args(self):
+        # https://mxnet.apache.org/get_started/build_from_source
         args = [
-            'CC=%s' % self.compiler.cc,
-            'CXX=%s' % self.compiler.cxx,
-            'MSHADOW_PATH=%s' % spec['mshadow'].prefix,
-            'PS_PATH=%s' % spec['ps-lite'].prefix,
-            'USE_OPENMP=%s' % ('1' if '+openmp' in spec else '0'),
-            'USE_CUDA=%s' % ('1' if '+cuda' in spec else '0'),
-            'USE_CUDNN=%s' % ('1' if '+cuda' in spec else '0'),
-            'USE_OPENCV=%s' % ('1' if '+opencv' in spec else '0'),
-            'USE_PROFILER=%s' % ('1' if '+profiler' in spec else '0'),
+            self.define_from_variant('USE_CUDA', 'cuda'),
+            self.define_from_variant('USE_CUDNN', 'cudnn'),
+            self.define_from_variant('USE_OPENCV', 'opencv'),
+            self.define_from_variant('USE_OPENMP', 'openmp'),
+            self.define_from_variant('USE_LAPACK', 'lapack'),
+            self.define_from_variant('USE_MKLDNN', 'mkldnn'),
         ]
 
-        if '+opencv' in spec:
-            if spec.satisfies('@1.3.0'):
-                filter_file(
-                    '$(shell pkg-config --cflags opencv)',
-                    spec['opencv'].headers.include_flags,
-                    'Makefile', string=True
-                )
-                filter_file(
-                    '$(filter-out -lopencv_ts, '
-                    '$(shell pkg-config --libs opencv))',
-                    spec['opencv'].libs.link_flags,
-                    'Makefile', string=True
-                )
-            else:
-                args.extend(
-                    ['USE_OPENCV_INC_PATH=' +
-                        spec['opencv'].headers.directories[0],
-                     'USE_OPENCV_LIB_PATH=' +
-                        spec['opencv'].libs.directories[0]]
-                )
-
-        if 'openblas' in spec:
-            args.extend(['USE_BLAS=openblas'])
-        elif 'atlas' in spec or 'cblas' in spec:
-            args.extend(['USE_BLAS=atlas'])
-        else:
-            args.extend(['USE_BLAS=blas'])
-
-        if '+cuda' in spec:
-            args.extend(['USE_CUDA_PATH=%s' % spec['cuda'].prefix,
-                         'CUDNN_PATH=%s' % spec['cudnn'].prefix,
-                         'CUB_INCLUDE=%s' % spec['cub'].prefix.include])
-            # By default, all cuda architectures are built. Restrict only
-            # if a specific list of architectures is specified in cuda_arch.
-            if 'cuda_arch=none' not in spec:
-                cuda_flags = self.cuda_flags(self.spec.variants['cuda_arch'].value)
-                args.append('CUDA_ARCH={0}'.format(' '.join(cuda_flags)))
-
-        make(*args)
-
-    def install(self, spec, prefix):
-        # mxnet is just a shared library -- no need to install a bin tree
-
-        install_tree('include', prefix.include)
-        install_tree('lib', prefix.lib)
-
-        # install python bindings
-        if '+python' in spec:
-            # The python libs are in a separate dir, and it is necessary to change
-            # directory so that setup.py picks them up.
+        if '+cuda' in self.spec:
+            if 'cuda_arch=none' not in self.spec:
+                cuda_arch = ';'.join('{0:.1f}'.format(float(i) / 10.0) for i
+                                     in self.spec.variants['cuda_arch'].value)
+                args.append(self.define('MXNET_CUDA_ARCH', cuda_arch))
+
+            args.append(self.define_from_variant('USE_NCCL', 'nccl'))
+
+            # Workaround for bug in GCC 8+ and CUDA 10 on PowerPC
+            args.append(self.define(
+                'CMAKE_CUDA_FLAGS', self.compiler.cxx11_flag))
+
+        return args
+
+    @run_after('build')
+    def build_python(self):
+        if '+python' in self.spec:
             with working_dir('python'):
-                setup_py('install', '--prefix={0}'.format(prefix),
+                setup_py('build')
+
+    @run_after('install')
+    def install_python(self):
+        if '+python' in self.spec:
+            with working_dir('python'):
+                setup_py('install', '--prefix={0}'.format(self.prefix),
                          '--single-version-externally-managed', '--root=/')
+
+    def test(self):
+        """Attempts to import modules of the installed package."""
+
+        if '+python' in self.spec:
+            # Make sure we are importing the installed modules,
+            # not the ones in the source directory
+            for module in self.import_modules:
+                self.run_test(self.spec['python'].command.path,
+                              ['-c', 'import {0}'.format(module)],
+                              purpose='checking import of {0}'.format(module),
+                              work_dir='spack-test')