Revert "1.4.0rc code change2"

This reverts commit 3f7eca3d.

build/env.yml

@@ -10,7 +10,7 @@ dependencies:
   - nbsphinx==0.3.5
   - recommonmark==0.4.0
   - https://github.com/mli/notedown/tarball/master
-  - mxnet-cu92==1.4.0b20181207
+  - mxnet-cu92==1.2.0
   - gluonbook==0.8.5
   - jieba==0.39
   - awscli

chapter_computer-vision/fcn.md

@@ -161,12 +161,13 @@ for i, cm in enumerate(gb.VOC_COLORMAP):
     colormap2label[(cm[0] * 256 + cm[1]) * 256 + cm[2]] = i
 voc_dir = gb.download_voc_pascal(data_dir='../data')
 
+num_workers = 0 if sys.platform.startswith('win32') else 4
 train_iter = gdata.DataLoader(
     gb.VOCSegDataset(True, crop_size, voc_dir, colormap2label), batch_size,
-    shuffle=True, last_batch='discard', num_workers=4)
+    shuffle=True, last_batch='discard', num_workers=num_workers)
 test_iter = gdata.DataLoader(
     gb.VOCSegDataset(False, crop_size, voc_dir, colormap2label), batch_size,
-    last_batch='discard', num_workers=4)
+    last_batch='discard', num_workers=num_workers)
 ```
 
 ## 训练

environment.yml

@@ -6,5 +6,5 @@ dependencies:
 - pandas=0.23.2
 - pip:
   - requests==2.18.4
-  - mxnet==1.4.0b20181207
+  - mxnet==1.2.0
   - gluonbook==0.8.5