Re: [PATCH 10/14] rust: add a build.rs script for tests

>
> On Mon, Oct 27, 2025 at 12:44:00AM +0000, brian m. carlson wrote:
> > diff --git a/Makefile b/Makefile
> > index 7e5a735ca6..7c36302717 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -2948,7 +2948,7 @@ scalar$X: scalar.o GIT-LDFLAGS $(GITLIBS)
> >  $(LIB_FILE): $(LIB_OBJS)
> >       $(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^
> >
> > -$(RUST_LIB): Cargo.toml $(RUST_SOURCES)
> > +$(RUST_LIB): Cargo.toml $(RUST_SOURCES) $(XDIFF_LIB) $(LIB_FILE) $(REFTABLE_LIB)
> >       $(QUIET_CARGO)cargo build $(CARGO_ARGS)
>
> We have recently removed the separare xdiff and reftable libraries, so
> it shouldn't be necessary to have these anymore.

> But one thing I'm curious about: don't we have a circular dependency
> between the Rust and C library now? I guess that's somewhat expected, as
> we'll want to call Rust from C and vice versa. But on the Meson side I
> think we need to adjust our logic so that we don't pull the Rust library
> into libgit.a to break this cycle.
>
> > diff --git a/build.rs b/build.rs
> > new file mode 100644
> > index 0000000000..136d58c35a
> > --- /dev/null
> > +++ b/build.rs
> > @@ -0,0 +1,21 @@
> > +// This program is free software; you can redistribute it and/or modify
> > +// it under the terms of the GNU General Public License as published by
> > +// the Free Software Foundation: version 2 of the License, dated June 1991.
> > +//
> > +// This program is distributed in the hope that it will be useful,
> > +// but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > +// GNU General Public License for more details.
> > +//
> > +// You should have received a copy of the GNU General Public License along
> > +// with this program; if not, see <https://www.gnu.org/licenses/>.
> > +
> > +fn main() {
> > +    println!("cargo::rustc-link-search=.");
> > +    println!("cargo::rustc-link-search=reftable");
> > +    println!("cargo::rustc-link-search=xdiff");
> > +    println!("cargo::rustc-link-lib=git");
> > +    println!("cargo::rustc-link-lib=reftable");
> > +    println!("cargo::rustc-link-lib=z");
> > +    println!("cargo::rustc-link-lib=xdiff");
> > +}
>
> How do we ensure that the correct libraries are linked here? E.g. for
> libz, if there are multiple such libraries, which one gets precedence?