Re: [PATCH] Cargo build product directory: CARGO_TARGET_DIR

[Thomas Klausner <wiz%NetBSD.org@localhost>]

On Thu, Feb 06, 2025 at 02:43:20PM +0000, Taylor R Campbell wrote:
> > Date: Thu, 6 Feb 2025 15:31:52 +0100
> > From: Thomas Klausner <wiz%NetBSD.org@localhost>
> > 
> > ===> Installing for ast-grep-0.34.4
> > => Generating pre-install file lists
> > error: found a virtual manifest at `/scratch/devel/ast-grep/work/ast-grep-0.34.4/Cargo.toml` instead of a package manifest
> > *** Error code 101
> > 
> > The code in lang/rust/cargo.mk basically expands to:
> > 
> > cd ${WRKSRC} && /usr/pkg/bin/cargo install --path . --root /scratch/devel/ast-grep/work/.destdir/usr/pkg --offline -j16
> > 
> > Does anyone know what this error wants to tell us, and how to get
> > around it?
> 
> It's a common issue -- for some reason while you can do recursive
> `cargo build' there's no recursive `cargo install':
> 
> https://github.com/rust-lang/cargo/issues/4101
> https://github.com/rust-lang/cargo/issues/7124
> https://github.com/rust-lang/cargo/issues/7599
> https://github.com/rust-lang/cargo/issues/7194
> https://users.rust-lang.org/t/cargo-install-workspace/29145
> https://stackoverflow.com/questions/61189179/found-a-virtual-manifest-at-path-instead-of-a-package-manifest

Thanks for digging these up. Annoying...

> So the package needs to either:
> 
> (a) install the files manually, or
> (b) explicitly specify all the sub-crates with `--path' instead of
>     using `--path .'.
> 
> The latter requires a slightly more invasive change -- and I'd like to
> hold that off until the cross-build patch is merged, because changing
> the `--path' arguments will cause more merge conflicts to resolve and
> test.

Sure.

> > Even if we don't find a fix this, I think if we add a variable
> > CARGO_BINARIES and add a rule in cargo.mk to install the files listed
> > in it manually (with basically the do-install from your mail above),
> > we can limit the scope of the variable you want to introduce to that
> > file.
> 
> Fine by me but the cargo.mk change to define CARGO_TARGET_DIR will
> still be needed for that!

Yes, but we only have it in cargo.mk and don't need to learn the
variable name and spread it all over pkgsrc's rust package
Makefiles. Less mental load.

But of course it's orthogonal to your proposal, we can clean it up
afterwards.
 Thomas