The previous URL did not contain the patch version and therefore there
were hash changes to the fetched files. Switch to a more stable URL.
The pdf-a4 file format seems to be generated only for the .0 patch
release, so it is missing for later releases.
When instantiating an environment with the Python interpreter built
with both free threading (aka. without GIL) and `pydebug`, the value
of `passthru.executable` doesn't match any installed file. This was
noticed when building CI pipelines that require the Python interpreter
built with both debug features and free threading.
The cause is that `executable` was built from `libPrefix`, which only
tracks the `t` suffix from `--without-gil` and not the `d` suffix from
`--with-pydebug`. `libPrefix` doubles as the stdlib install directory,
and cpython deliberately shares that directory between debug and
non-debug builds of a given version, so the `d` is intentionally
absent there.
This slipped through because cpython only ever installs a
`python$VERSION -> python$LDVERSION` symlink (e.g. `python3.13 ->
python3.13d`). For debug-only builds the old code happened to ask for
`python3.13`, which is that symlink, so it worked by accident. For
FT+debug, `libPrefix` is `python3.13t`, but cpython installs no such
file; only `python3.13` (symlink) and `python3.13td` (binary).
Fix: append `d` to `executable` (and to the `cp<ver>` wheel ABI tag in
`pythonABITags`) when `enableDebug` is true.
Reproducer for the problem as a bash script:
```bash
set -euo pipefail
nixpkgs="${1:-<nixpkgs>}" # Either custom path if provided, or just <nixpkgs>
read -r -d '' expr <<EOF || true
let
pkgs = import ${nixpkgs} { };
py = pkgs.python313FreeThreading.override {
enableDebug = true;
self = py;
pythonAttr = "python313FreeThreading";
};
in py
EOF
executable=$(nix-instantiate --eval --json --expr "($expr).executable" | tr -d '"')
echo "passthru.executable = ${executable}"
out=$(nix-build --no-out-link --expr "$expr")
echo "store path: ${out}"
if [[ -e "${out}/bin/${executable}" ]]; then
echo "result: OK (binary exists)"
exit 0
fi
echo "result: FAIL (${out}/bin/${executable} not found)"
echo "actually installed:"
ls "${out}/bin/" | grep '^python3\.' | sed 's/^/ /'
exit 1
```
