- add " -std=gnu17" to `env.NIX_CFLAGS_COMPILE`
Fixes build failure with gcc15:
```
In file included from Include/Python-ast.h:3,
from Python/bltinmodule.c:4:
Include/asdl.h:9:15: error: cannot use keyword 'false' as enumeration constant
9 | typedef enum {false, true} bool;
| ^~~~~
Include/asdl.h:9:15: note: 'false' is a keyword with '-std=c23' onwards
Include/asdl.h:9:28: error: expected ';', identifier or '(' before 'bool'
9 | typedef enum {false, true} bool;
| ^~~~
Include/asdl.h:9:28: warning: useless type name in empty declaration
In file included from Include/Python-ast.h:3,
from Python/compile.c:26:
Include/asdl.h:9:15: error: cannot use keyword 'false' as enumeration constant
9 | typedef enum {false, true} bool;
| ^~~~~
Include/asdl.h:9:15: note: 'false' is a keyword with '-std=c23' onwards
Include/asdl.h:9:28: error: expected ';', identifier or '(' before 'bool'
9 | typedef enum {false, true} bool;
| ^~~~
```
As documented in https://packaging.python.org/en/latest/specifications/platform-compatibility-tags/#abi-tag.
This is useful to check whether a wheel is compatible with a certain interpreter. [Pyproject.nix](https://github.com/pyproject-nix/pyproject.nix) has [functions to perform wheel compatibility checking](https://pyproject-nix.github.io/pyproject.nix/lib/pypa.html#function-library-lib.pypa.isWheelFileCompatible) against a Python interpreter, and has computed interpreter ABI tags itself.
The recent addition of free threading (`python313FreeThreading`) complicates this by not being introspectable:
A GIL Python (non free-threaded) has an ABI tag `cp313` while the free-threaded Python has `cp313t`, but the package doesn't communicate whether `enableGIL` is true or false, leaving no way to compute the tag.
The same goes for if debugging support was added to the derivation: A `d` suffix would need to be added.
Additionally ABI tags has no defined format and can really only be accurately computed by having insight into how the ABI tags are used by a specific interpreter, meaning that the only correct place to compute ABI tags is within the context of a particular Python derivation.
While this has no immediate use within nixpkgs it could be used as a basis to provide compatibility assertions regarding wheel compat at eval time.
The intermediate pythonMinimal build that uses the glibc from bootstrap
files cannot currently be built with PIE, because the Scrt.o startup
script is missing in there.
Martin Weinelt