gh-127405: Remove dead code in sysconfig._get_pybuilddir()

[XuehaiPan]

The return value for get_config_var('Py_DEBUG') is one of 0, 1, None. It cannot be a str.

• Issue: Set sys.abiflags on Windows #127405

[XuehaiPan]

How can I add the "skip news" label?

[brianschubert]

Hmm, I think something might be outdated here. When I build with --with-pydebug, the build dir is build/lib.<platform>-<version>, not build/lib.<platform>-<version>-pydebug:

$ rm -r build
$ make clean && ./configure --with-pydebug --prefix=$(pwd) && make -j

$ ./python -c 'import sysconfig; print(sysconfig.get_config_var("Py_DEBUG"))'
1

$ ls -l build 
total 16
drwxrwxr-x 3 brian brian 12288 Mar 31 09:17 lib.linux-x86_64-3.14
drwxrwxr-x 2 brian brian  4096 Mar 31 09:17 scripts-3.14

Maybe the right fix is to remove that branch altogether?

How can I add the "skip news" label?

If any user-facing behavior changes, there should be a news entry. Right now this PR changes where -m sysconfig --generate-posix-vars writes its output files, so that would require a news entry.

[XuehaiPan]

Maybe the right fix is to remove that branch altogether?

Move to this approach.

[davidlowryduda]

I don't see any way for this to be called, but I note that this behavior is tied to

cpython/Tools/wasm/wasi.py

Line 216 in e9556e1

pydebug = lib_dir.endswith("-pydebug")

I think this aspect of the WASM build is broken, and if this code can be deleted then perhaps that trail can too.

[XuehaiPan]

The complexity of fixing the WASM build with the correct path is beyond what I expected.

[FFY00]

I think you are trying to fix GH-131769. GH-131761 should address it if it gets merged.

GH-131844 should fix the debug WASM builds, and GH-131855 proposes a more reliable way to set the stack size limit.