LD_LIBRARY_PATH issues on pip-installed Halide.

[allemangD]

I'm observing a strange behavior but I'm not sure if it isn't just user error. One one of my Linux machines, the pip-installed Halide python bindings work beautifully. On another, however, I encounter strange missing symbol errors.

$ python
Python 3.10.19 (main, Oct 31 2025, 23:02:46) [Clang 21.1.4 ] on linux
>>> import halide
ImportError: .venv/lib/python3.10/site-packages/halide/halide_.cpython-310-x86_64-linux-gnu.so: undefined symbol: _ZN6Halide4Func15never_partitionERKSt6vectorINS_9VarOrRVarESaIS2_EE

(I observe the same behavior with Python 3.13, installed via uv or pip.)

I can work around the issue by setting LD_LIBRARY_PATH or by loading libHalide.so with ctypes; but I am confused why this might be happening only on one of my machines with otherwise similar platforms.

$ LD_LIBRARY_PATH=.venv/lib/python3.10/site-packages/halide/lib64/ python
Python 3.10.19 (main, Oct 31 2025, 23:02:46) [Clang 21.1.4 ] on linux
>>> import halide

$ python
Python 3.10.19 (main, Oct 31 2025, 23:02:46) [Clang 21.1.4 ] on linux
>>> import ctypes
>>> ctypes.cdll.LoadLibrary('.venv/lib/python3.10/site-packages/halide/lib64/libHalide.so')
<CDLL '.venv/lib/python3.10/site-packages/halide/lib64/libHalide.so', handle 5c0aa718ba10 at 0x7858a33ac8e0>
>>> import halide

Does anyone have suggestions on what configs I should check to avoid the workarounds and get both machines working with simple import halide?

[alexreinking]

I wish I could say I've seen this before! Can you try running the Python interpreter with LD_DEBUG=all?

Docs: https://man7.org/linux/man-pages/man8/ld.so.8.html

[allemangD]

Great suggestion. Indeed it was user error. 🤦 I had a very old libHalide.so in my .local/lib on that machine that I'd forgotten about. (Version 16!) and that symbol happened to be the first one which wasn't defined. Removing that old version fixed the issue.

It does raise a question: is it possible to somehow move the python package's lib64 to higher precedence to avoid collision with system installations?

Or, at least, a versioned library name libHalide.so.21.0.0 would have avoided this particular issue but not the general collision problem.

[alexreinking]

"The Halide Python bindings can load a foreign libHalide.so" is a bug. Can you please open an issue?

[allemangD]

Sure. #8866