Packages are built in a well-known, explicit location: ${WRKDIR}/pkg. Wheels,
however, are left wherever the PEP 517 backend happens to put them under
${WRKSRC} -- and that location isn't even consistent across backends (e.g.
"dist/" for build/setuptools, "target/wheels/" for maturin) -- which makes
them hard for external tooling such as poudriere to locate reliably.
Point PEP517_BUILD_CMD and PEP517_INSTALL_CMD at the same fixed location,
${WRKDIR}/whl, so wheels follow the same explicit convention as packages.
Ports that invoke a build tool directly rather than through PEP517_BUILD_CMD
(e.g. maturin) should likewise pass ${WRKDIR}/whl as their own output
directory, rather than a location of their own choosing, so the build and
install sides cannot drift apart.
PR: 290653