g++ 不可用，如果使用 conda：`conda install m2w64-toolchain`答案

【问题标题】：g++ not available, if using conda: `conda install m2w64-toolchain`g++ 不可用，如果使用 conda：`conda install m2w64-toolchain`
【发布时间】：2018-02-17 05:59:10
【问题描述】：

在遵循这些教程Neural net 期间，在运行 test.py 文件时，我收到了这些异常和警告。我已经尝试过以前的建议，但没有任何效果。

WARNING (theano.configdefaults): g++ not available, if using conda: `conda install m2w64-toolchain`
C:\ProgramData\Anaconda3\lib\site-packages\theano\configdefaults.py:560: UserWarning: DeprecationWarning: there is no c++ compiler.This is deprecated and with Theano 0.11 a c++ compiler will be mandatory
  warnings.warn("DeprecationWarning: there is no c++ compiler."
WARNING (theano.configdefaults): g++ not detected ! Theano will be unable to execute optimized C-implementations (for both CPU and GPU) and will default to Python implementations. Performance will be severely degraded. To remove this warning, set Theano flags cxx to an empty string.
WARNING (theano.tensor.blas): Using NumPy C-API based implementation for BLAS functions.

任何适当的修复将不胜感激。

尝试使用 conda install m2w64-toolchain 之后。另一个错误来了，

*You can find the C code in this temporary file: C:\Users\CERTAI~1\AppData\Local\Temp\theano_compilation_error_7bgw9_s9
Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\gof\lazylinker_c.py", line 75, in <module>
    raise ImportError()
ImportError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\gof\lazylinker_c.py", line 92, in <module>
    raise ImportError()
ImportError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\shubhamprojectwork\all Work 2018\kaggle\DeepLearningPython35-master\DeepLearningPython35-master\test.py", line 156, in <module>
    import network3
  File "C:\shubhamprojectwork\all Work 2018\kaggle\DeepLearningPython35-master\DeepLearningPython35-master\network3.py", line 37, in <module>
    import theano
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\__init__.py", line 110, in <module>
    from theano.compile import (
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\compile\__init__.py", line 12, in <module>
    from theano.compile.mode import *
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\compile\mode.py", line 11, in <module>
    import theano.gof.vm
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\gof\vm.py", line 673, in <module>
    from . import lazylinker_c
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\gof\lazylinker_c.py", line 127, in <module>
    preargs=args)
  File "C:\ProgramData\Anaconda3\lib\site-packages\theano\gof\cmodule.py", line 2359, in compile_str
    (status, compile_stderr.replace('\n', '. ')))
Exception: Compilation failed (return status=1): C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `_import_array':
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1470: undefined reference to `__imp_PyExc_ImportError'
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1476: undefined reference to `__imp_PyExc_AttributeError'
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1481: undefined reference to `__imp_PyCapsule_Type'
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1482: undefined reference to `__imp_PyExc_RuntimeError'
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1497: undefined reference to `__imp_PyExc_RuntimeError'
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1505: undefined reference to `__imp_PyExc_RuntimeError'
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1511: undefined reference to `__imp_PyExc_RuntimeError'
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1521: undefined reference to `__imp_PyExc_RuntimeError'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o:C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/__multiarray_api.h:1533: more undefined references to `__imp_PyExc_RuntimeError' follow
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `NpyCapsule_Check':
. C:/ProgramData/Anaconda3/lib/site-packages/numpy/core/include/numpy/npy_3kcompat.h:456: undefined reference to `__imp_PyCapsule_Type'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `unpack_list_of_ssize_t':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:48: undefined reference to `__imp_PyExc_TypeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:58: undefined reference to `__imp_PyExc_IndexError'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `CLazyLinker_init':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:352: undefined reference to `__imp_PyExc_IndexError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:370: undefined reference to `__imp_PyExc_IndexError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:385: undefined reference to `__imp_PyExc_IndexError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:389: undefined reference to `__imp_PyExc_IndexError'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o:C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:393: more undefined references to `__imp_PyExc_IndexError' follow
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `CLazyLinker_init':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:405: undefined reference to `__imp_PyExc_TypeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:420: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:426: undefined reference to `__imp_PyExc_IndexError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:440: undefined reference to `__imp_PyExc_TypeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:444: undefined reference to `__imp__Py_NoneStruct'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `c_call':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:545: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:545: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:545: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:546: undefined reference to `__imp__Py_NoneStruct'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o:C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:546: more undefined references to `__imp__Py_NoneStruct' follow
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `lazy_rec_eval':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:618: undefined reference to `__imp_PyExc_IndexError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:641: undefined reference to `__imp_PyExc_TypeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:649: undefined reference to `__imp_PyExc_ValueError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:657: undefined reference to `__imp_PyExc_IndexError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:708: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:715: undefined reference to `__imp_PyExc_TypeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:721: undefined reference to `__imp_PyExc_TypeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:771: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:771: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:772: undefined reference to `__imp__Py_NoneStruct'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `CLazyLinker_call':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:814: undefined reference to `__imp_PyExc_RuntimeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:826: undefined reference to `__imp_PyExc_RuntimeError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:839: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:839: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:840: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:849: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:849: undefined reference to `__imp__Py_NoneStruct'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o:C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:850: more undefined references to `__imp__Py_NoneStruct' follow
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `CLazyLinker_call':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:894: undefined reference to `__imp_PyExc_AssertionError'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:937: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:937: undefined reference to `__imp__Py_NoneStruct'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:938: undefined reference to `__imp__Py_NoneStruct'
. C:\Users\CERTAI~1\AppData\Local\Temp\ccFdFXU1.o: In function `CLazyLinker_set_allow_gc':
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:973: undefined reference to `__imp_PyBool_Type'
. C:/Users/Certainty1/AppData/Local/Theano/compiledir_Windows-10-10.0.16299-SP0-Intel64_Family_6_Model_142_Stepping_9_GenuineIntel-3.6.1-64/lazylinker_ext/mod.cpp:976: undefined reference to `__imp__Py_TrueStruct'
. collect2.exe: error: ld returned 1 exit status
.*

【问题讨论】：

“先前的建议”是什么意思？你试过运行conda install m2w64-toolchai吗？
是的@AnthonyKong 之后出现另一个错误，上面写着这些，collect2.exe: error: ld returned 1 exit status

标签： python tensorflow g++ theano conda

【解决方案1】：

根据我的个人经验，连续错误是由于 windows 的 python*.dll 不存在（或根本找不到）引起的。你可以通过'conda install libpython'来解决这个问题

【讨论】：

【解决方案2】：

我有同样的错误。在我的电脑上，我有 python 3.6。我这样做了：
1. 我卸载并重新安装了 conda。
2. 我使用 conda 和 python 3.5 创建了一个环境
3.在环境中安装m2w64-toolchain

它成功了！

【讨论】：

【解决方案3】：

对于那些做了所有事情的人，据说是on this page，但仍然遇到以下消息（这意味着您的性能将显着降低）：

WARNING (theano.configdefaults): g++ not available, if using conda: `conda install m2w64-toolchain`
C:\Users\user\miniconda3\lib\site-packages\theano\configdefaults.py:560: UserWarning: DeprecationWarning: there is no c++ compiler.This is deprecated and with Theano 0.11 a c++ compiler will be mandatory
warnings.warn("DeprecationWarning: there is no c++ compiler."
WARNING (theano.configdefaults): g++ not detected ! Theano will be unable to execute optimized C-implementations (for both CPU and GPU) and will default to Python implementations. Performance will be severely degraded. To remove this warning, set Theano flags cxx to an empty string.
WARNING (theano.tensor.blas): Using NumPy C-API based implementation for BLAS functions.

我可以找到此消息的来源：它位于您的 python 环境安装路径<path_to_your_python_env>/Lib/site-packages/theano/misc/windows.py。在 subprocess_Popen 方法中，您将找到字符串

params['shell'] = True

您需要删除或注释掉的内容。通过调用此方法来检查 g++ 和 c++ 编译器是否存在。并且使用shell=True 参数会在Windows 机器上导致一个未找到的错误（它被静音，所以你永远不会知道[老实说，我不知道是谁决定这样做的]）。该错误很可能是因为传递给subprocess.Popen 的系统调用命令被某些符号损坏：it is recommended 在使用shell=True 时使用字符串args 参数，Theano 的作者不遵守（他们传递列表)。

如果 shell 为 True，建议将 args 作为字符串而不是序列传递。

在我注释掉这个字符串并尝试导入 Theano/PyMC3 后，消息消失了，我可以享受这些令人惊叹的工具的顶级性能。

【讨论】：

您发布第一个解决方案的链接不起作用，还有另一个链接吗？我会为此提供帮助
@CelsaPardoAraujo，我更新了链接，看起来 Theano 的文档和支持已移至 PyMC 团队。

【解决方案4】：

我昨天遇到了同样的问题。

我已经下载并安装了 g++，因为 theano 需要它才能工作

请点击此链接了解如何下载和安装

http://www.instructables.com/id/How-to-Install-MinGW-GCCG-Compiler-in-Windows-XP78/

将路径添加到我的环境后，我卸载并重新安装了 anaconda。

我为 python 3.5 创建了一个新环境激活它然后我按照这里的说明安装theano

http://deeplearning.net/software/theano/install_windows.html

他们的步骤将我的 python 降级到 2.7

然后我做了以下

1: pip install 未来 2：pip安装枕头 3：康达安装nb_conda_kernels 4：点安装未来--升级 5：添加环境变量——MKL_THREADING_LAYER=GNU 6：重新启动我的终端，一切正常。

我不需要为后续环境执行这些初始步骤激活python 3.5环境后，做

conda install theano 设置我需要的一切

希望对你有帮助

【讨论】：