XXX: If you tried the approach before, please remove devel/cxxbridge-cmd

Please find a new approach to make rust and cmake work together with
devel/corrosion. The new approach leaves devel/corrosion as it is and
does all the work in the consumer port. For graphics/cxx-rust-cssparser
it looks like this (I also tested it with another port):

1. We ship our own Cargo.lock for cxxbridge-cmd so the build resolves
   against the modcargo vendored crates instead of reaching out to
   crates.io.
1.1. We provide a crates.inc that lists all crates, both for
     MODCARGO_CARGOTOML and for the cxxbridge-cmd version.

2. We replace Cargo.lock, so we drop its entry from
   .cargo-checksum.json, because otherwise cargo's integrity check fails
   the --locked build.

corrosion builds cxxbridge-cmd during the build step, but everything it
needs is already present in MODCARGO_VENDOR_DIR.

If this is OK for everyone, I would like to ask for OKs to import it.

I tested this with the KDE Plasma 6.7 update at runtime.

Here is the base idea:

MODULES =		devel/cmake \
			devel/cargo

MODCARGO_BUILD =	No
MODCARGO_INSTALL =	No

MODCARGO_CARGOTOML =	${WRKSRC}/rust/Cargo.toml

BUILD_DEPENDS =		devel/corrosion

CONFIGURE_ENV +=	CARGO_HOME=${WRKDIR}/cargo-home
MAKE_ENV +=		CARGO_HOME=${WRKDIR}/cargo-home

WRKDIST =		${WRKDIR}/cxx-rust-cssparser-v${VERSION}-2c5cd92c14164e6da2b98beba1edeaecdc1445d1

CXXBRIDGE_V =		1.0.194
CXXBRIDGE_LOCKFILE =	cxxbridge-cargo.lock

pre-configure:
	# We ship our own Cargo.lock for cxxbridge-cmd so the build resolves
	# against the vendored crates instead of reaching out to crates.io
	cp ${FILESDIR}/${CXXBRIDGE_LOCKFILE} \
		${MODCARGO_VENDOR_DIR}/cxxbridge-cmd-${CXXBRIDGE_V}/Cargo.lock
	# We replaced Cargo.lock so we drop its entry from .cargo-checksum.json
	# because otherwise cargo's integrity check fails the --locked build.
	cd ${MODCARGO_VENDOR_DIR}/cxxbridge-cmd-${CXXBRIDGE_V} && \
		sed -i 's,"Cargo.lock":"[0-9a-f]*"\,,,' .cargo-checksum.json
	mkdir -p ${WRKDIR}/cargo-home
	printf '%s\n' \
		'[source.crates-io]' \
		'replace-with = "modcargo"' \
		'[source.modcargo]' \
		'directory = "${MODCARGO_VENDOR_DIR}"' \
		'[net]' \
		'offline = true' \
		> ${WRKDIR}/cargo-home/config.toml

# This file includes MODCARGO_CARGOTOML and CXXBRIDGE_LOCKFILE crates.
.include "crates.inc"

• corrosion_and_cxx-rust-cssparser.tar.gz (12K)