Wrong output for python3-config --ldflags

[ppwwyyxx]

Just install anaconda for python3.6 on macos sierra, with the graphical installer.
After the installation:

$ python3-config --ldflags
-lpython3.6m -ldl -framework CoreFoundation -Wl,-stack_size,1000000 -framework CoreFoundation

Two things:

1. It should include -L/Users/xxx/anaconda/lib in ldflags as well, otherwise a compiler cannot find -lpython3.6m. This is done in anaconda Linux, also in non-conda python.
2. Why -stack_size,1000000? Clang complains that this flag is only valid when linking an executable, while I'm linking a shared library.

[nofacer]

Hi I just came across the same error when build another project and finally found the solution. Just modify the makefile manually like this:
PYLIBS := -L/Users/Your_name/anaconda3/lib/python3.6/config-3.6m-darwin -lpython3.6m -ldl -framework CoreFoundation

[Atry]

This bug is introduced by CPython:
https://github.com/python/cpython/blob/8c9bb72e8b6474ae722f7d6521cfb3cb2e26e3c5/configure.ac#L2614

It has been workaround in anaconda's python 3.5:
ContinuumIO/anaconda-recipes@931bfba

However, other 3.x versions of anaconda's python still produce wrong ldflags.

[mingwandroid]

Please explain what's wrong with our ldflags.

…

On Jan 31, 2018 5:54 AM, "杨博 (Yang Bo)" ***@***.***> wrote: This bug is introduced by CPython, and has been fixed in anaconda's python 3.5: ***@***.*** <ContinuumIO/anaconda-recipes@931bfba> However, other 3.x versions of anaconda's python still produce wrong ldflags. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#1761 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AA_pdBpyRv8OqjnlTRylwRxwq9AU87U3ks5tQAAjgaJpZM4Nly7l> .

[Atry]

@mingwandroid Wrong ldflags as described in @ppwwyyxx's post.

[mingwandroid]

python3-config --ldflags returns the linker flags for embedding Python in another application, it does not give the linker flags for compiling a Python extension module. To get those you need to run the following:

python -c "import sysconfig; print(sysconfig.get_config_vars('LDSHARED'))"

[mingwandroid]

It should include -L/Users/xxx/anaconda/lib

.. now-a-days, (since AD 5.0) our Python interpreter is statically linked on macOS and thus prefers to be statically linked, so:

python3-config --ldflags
-L/opt/conda/lib/python3.6/config-3.6m-darwin -lpython3.6m -ldl -framework CoreFoundation -Wl,-stack_size,1000000 -framework CoreFoundation
ls /opt/conda/lib/python3.6/config-3.6m-darwin
lrwxr-xr-x  1 rdonnelly  admin     21 23 Jan 12:14 libpython3.6m.a -> ../../libpython3.6m.a

.. is just fine.

[saraedum]

@mingwandroid Interesting, so Debian/Ubuntu gets this wrong on their man-page: http://manpages.ubuntu.com/manpages/xenial/en/man1/i386-linux-gnu-python2.7-config.1.html

[mingwandroid]

Yes it looks like they do indeed get it wrong here! You should note, the python build scripts from Debian/Ubuntu are what inspired me to switch to a static interpreter, that and the prompting of @pitrou

[saraedum]

Ok. I wrote an email to the author of the man-page.