Should I take care of "could not determine Graal.Python's *** path"? #535

eomasters-repos · 2025-08-15T14:35:07Z

eomasters-repos
Aug 15, 2025

When I enable verbose logging, I see the following lines:

[python::Python3Core] FINE: Initial locations:
	Language home: null
	SysPrefix: 
	BaseSysPrefix: 
	CoreHome: 
	StdLibHome: 
	CAPI: 
	JNI library: 
	Home candidate: C:\Users\marco\.snap\auxdata\eomtbxpro\graalpy\bin
[python::Python3Core] FINE: Updated locations:
	Language home: C:\Users\marco\.snap\auxdata\eomtbxpro\graalpy\bin
	SysPrefix: 
	BaseSysPrefix: 
	CoreHome: 
	StdLibHome: 
	Executable: C:\Users\marco\snap_code\GraalPyTest\venv\Scripts\python.exe
	CAPI: 
	JNI library: 
[python::PythonContext] WARNING: could not determine Graal.Python's core path - you may need to pass --python.CoreHome.
[python::PythonContext] WARNING: could not determine Graal.Python's sys prefix path - you may need to pass --python.SysPrefix.
[python::PythonContext] WARNING: could not determine Graal.Python's standard library path. You need to pass --python.StdLibHome if you want to use the standard library.
[python::PythonContext] WARNING: could not determine Graal.Python's C API library path. You need to pass --python.CAPI if you want to use the C extension modules.

I wonder If I should worry about and set the paths explicitly? And which paths are those?

msimacek · 2025-08-15T15:08:11Z

msimacek
Aug 15, 2025
Collaborator

It's definitely a problem, but you shouldn't set the paths manually, GraalPy should be able to find them. How do you execute GraalPy and how did you create the virtualenv? And what GraalPy version is this?

0 replies

eomasters-repos · 2025-08-16T12:59:58Z

eomasters-repos
Aug 16, 2025
Author

Thanks. Good to know. I already thought that graalpy should be able to figure out the paths.
I'm using graalpy-community-24.2.2-windows-amd64.zip in my maven pom I use

org.graalvm.polyglot:polyglot:24.2.2
org.graalvm.polyglot:python:24.2.2
org.graalvm.python:python-language:24.2.2

And I execute the Java project with graalvm-ce-23.0.2.

I setup the engine and the context manually in my project.
It could be that something went wrong. I did quite some experiments.
I'll extract the essential code of my project and try to reproduce it. Maybe I fix it on the way, or I can provide a better report.

0 replies

eomasters-repos · 2025-08-18T12:10:57Z

eomasters-repos
Aug 18, 2025
Author

Meanwhile I'm confused and a bit desperate. Probably I'm doing something wrong, but I don't see it.
Sorry for the lengthy report but I don't know how to make it short. And thanks to everyone who is looking into it.

I have now created a simple projecte where I do basically the same as in my real project.
https://github.com/eomasters-repos/GraalPySetup

I'm using, as said

org.graalvm.polyglot:polyglot:24.2.2
org.graalvm.polyglot:python:24.2.2
org.graalvm.python:python-language:24.2.2

As JVM I'm using the latest graalvm-jdk-24.0.2+11.1
And my Graalpython is Python version: 3.11.7 [Graal, Oracle GraalVM, Java 24.0.2 (amd64)]
All is executed on Win11

First, I should say that now in the sample project are initialised, but still not in my real project even though I have the same configuration, I think:

[python::Python3Core] FINE: Initial locations:
	Language home: null
	SysPrefix: 
	BaseSysPrefix: 
	CoreHome: 
	StdLibHome: 
	CAPI: 
	JNI library: 
	Home candidate: C:\Users\marco\.snap\auxdata\eomtbxpro\graalpy\bin
[python::Python3Core] FINE: Initial locations:
	Language home: null
	SysPrefix: 
	BaseSysPrefix: 
	CoreHome: 
	StdLibHome: 
	CAPI: 
	JNI library: 
	Home candidate: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c
[python::Python3Core] FINE: Updated locations:
	Language home: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c
	SysPrefix: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c
	BaseSysPrefix: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c
	CoreHome: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c\lib-graalpython
	StdLibHome: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c\Lib
	Executable: C:\Users\marco\IdeaProjects\GraalPySetup\example\venv\Scripts\python.exe
	CAPI: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c\lib-graalpython
	JNI library: C:\Users\marco\AppData\Local\org.graalvm.polyglot\python\python-home\86aae279f9357aa0b2b83ce56850e28c7b84fe1c\lib-graalpython

But still can't use numpy. The only numpy version I can install using pip is 1.26.4. But when importing it I get the error:

Traceback (most recent call last):
  File "C:\Users\marco\IdeaProjects\GraalPySetup\example\src\code.py", line 12, in <module>
    import numpy as np
  File "C:\Users\marco\IdeaProjects\GraalPySetup\example\venv\Lib\site-packages\numpy\__init__.py", line 148, in <module>
    raise ImportError(msg) from e
ImportError: Error importing numpy: you should not try to import numpy from
        its source directory; please exit the numpy source tree, and relaunch
        your python interpreter from there.
Exception in thread "main" org.graalvm.polyglot.PolyglotException
	at org.graalvm.polyglot.Context.eval(Context.java:416)
	at Main.main(Main.java:50)

Installation of later numpy versions like 2.2.4, already the package installation fails.

auto-patching C API usages in C:\Users\marco\AppData\Local\Temp\pip-install-wv5pzjaq\numpy_fa5565c7103d4b8495c575fb841aaeb1\numpy\_core\include\numpy\ndarrayobject.h
<shortened>
auto-patching C API usages in C:\Users\marco\AppData\Local\Temp\pip-install-wv5pzjaq\numpy_fa5565c7103d4b8495c575fb841aaeb1\numpy\_core\src\umath\_rational_tests.c
  Looking for GraalPy patches for numpy
  Patching package numpy using numpy-2.2.4.patch
ERROR: Could not install packages due to an OSError: [Errno 5] I/O error: 'patch.exe'

I have the folder where the patch.exe is located on the PATH. I'm testing this with the following command and the patch window is shown.

new ProcessBuilder("cmd", "/c", "patch.exe").start()

Strangely I don't get the _add_dll_directory error here.

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Should I take care of "could not determine Graal.Python's *** path"? #535

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