Linux环境Python3.6配置CPU运行Theano时导入报错

Hey there, let's get this Theano import issue sorted out for you. The root cause here is clear from the error messages: your Python 3.6 installation uses a static library (libpython3.6m.a) that wasn't compiled with the -fPIC (Position-Independent Code) flag. Theano needs this flag to build its C extensions as shared objects, which is why the linker is throwing that relocation error.

Step-by-Step Solutions #

1. Verify the Problem #

First, confirm that your Python library is indeed static and missing PIC support:

file /usr/local/lib/libpython3.6m.a

If the output says something like current ar archive, that confirms it's a static library without the necessary PIC flags.

2. Recompile Python 3.6 with Required Flags #

The most reliable fix is to recompile Python 3.6 with -fPIC and shared library support:

• Download the Python 3.6 source code from the official Python archive.
• Extract the source and navigate to the directory in your terminal.
• Run the configure command with the required flags:

  ./configure --enable-shared CFLAGS=-fPIC
  

• Compile and install:

  make
  sudo make install
  

• Update the system library cache to ensure the new shared library is recognized:

  sudo ldconfig
  

3. Reinstall Theano #

Once Python is recompiled, uninstall and reinstall Theano to ensure it builds against the new shared library:

pip uninstall -y theano
pip install theano

4. Alternative: Tweak Theano's Compile Flags (Less Reliable) #

If recompiling Python isn't an option right now, you can try forcing Theano to use -fPIC during its own compilation:

• Create or edit the Theano configuration file (~/.theanorc or /etc/theanorc):

  [gcc]
  cflags = -fPIC
  

• Save the file and try importing Theano again. Note that this might not resolve the issue entirely since the core problem is with the Python static library itself.

Why This Happens #

Position-Independent Code (PIC) allows shared libraries to be loaded at any memory address. When Python is compiled as a static library without -fPIC, Theano can't link its own dynamic extensions against it—hence the linker error about relocation R_X86_64_32S. Recompiling Python with shared library support and -fPIC fixes this by providing the type of library Theano needs.

内容的提问来源于stack exchange，提问作者Deepthi