rust-crate tools for handling binaries

[kentfredric]

So I've hit my first crate that can provide user-usable binaries, aho-corasick which ships binary aho-corasick-dot.

I'm mostly sure its just an example, but anyway.

What I've currently settled upon is:

1. Compile the binary with:

src_compile() {
	rust-crate_src_compile
	ecargo build --release --bins
}

2. Install the binary into /usr/lib/rust/binaries

src_install() {
	rust-crate_src_install
	exeinto "/usr/lib/rust/binaries/${P}"
	doexe "${CARGO_TARGET_DIR}/release/aho-corasick-dot"
}

3. employ alternatives.eclass to provide a symlink:

pkg_postinst() {
	alternatives_auto_makesym "/usr/bin/aho-corasick-dot" "/usr/lib/rust/binaries/aho-corasick-[0-9].[0-9].[0-9]/aho-corasick-dot"
}
pkg_postrm() {
	alternatives_auto_makesym "/usr/bin/aho-corasick-dot" "/usr/lib/rust/binaries/aho-corasick-[0-9].[0-9].[0-9]/aho-corasick-dot"
}

Though it would be very nice if the rust-crate eclass had some sort of mechanism for handling this generically.

Importantly, it probably needs "${PF}" not "${P}" or whatever, or not, not 100% sure right now. ( I suspect it should use the same naming convention as we use for the /crates/ dir, namely, using the upstream version data only in the path, and not allowing concurrent sub-revisions of the same upstream version ).

[kentfredric]

See also: #2

But it makes sense to me atm to have the layout:

/usr/lib/rust/benches/CRATENAME-CRATEVERSION/*  -> benchmark binaries from the crate
/usr/lib/rust/binaries/CRATENAME-CRATEVERSION/*  -> binaries from the crate
/usr/lib/rust/crates/CRATENAME-CRATEVERSION    -> crate source trees
/usr/lib/rust/examples/CRATENAME-CRATEVERSION/*  -> example binaries from the crate

Though only binaries are a good candidate for auto-symlinking to /usr/bin/

But I suspect an alternative of this might be more appealing to the FHS nerds.

/usr/lib/rust/crates/CRATENAME-CRATEVERSION    -> crate source trees
/usr/libexec/rust/crates/CRATENAME-CRATEVERSION/benches/*  -> benchmark binaries from the crate
/usr/libexec/rust/crates/CRATENAME-CRATEVERSION/bin/*  -> binaries from the crate
/usr/libexec/rust/crates/CRATENAME-CRATEVERSION/examples/*  -> example binaries from the crate

[kentfredric]

Or option 3:

/usr/lib/rust/crates/CRATENAME-CRATEVERSION    -> crate source trees
/usr/libexec/rust/crates/CRATENAME-CRATEVERSION/*  -> binaries from the crate
/usr/share/rust/crates/CRATENAME-CRATEVERSION/benches/*  -> benchmark binaries from the crate
/usr/share/rust/crates/CRATENAME-CRATEVERSION/examples/*  -> example binaries from the crate

[kentfredric]

Though worth mentioning at this time, 99.99% of rust benchmarks can't even compile on stable due to using nightly-only modules that are part of nightly-rust, but its worth thinking about for the academic idea that we might want them some day.