fix nightly build

In recent versions of the nightly / beta compilers, the use of linkme
causes linker errors. (dtolnay/linkme#94) This
is due to the new linker set as default in these versions.

Add linker flags to nightly builds to revert to the old linker
behaviour.

See:
  - dtolnay/linkme#88
  - https://blog.rust-lang.org/2024/05/17/enabling-rust-lld-on-linux.html

crates/conjure_core/Cargo.toml

@@ -3,6 +3,9 @@ name = "conjure_core"
 version = "0.0.1"
 edition = "2021"
 
+[build-dependencies]
+rustc_version = "0.2"
+
 [dependencies]
 conjure_macros = { path = "../conjure_macros" }
 enum_compatability_macro = { path = "../enum_compatability_macro" }

crates/conjure_core/build.rs

@@ -0,0 +1,18 @@
+use rustc_version::{version_meta, Channel};
+fn main() {
+    // Linkme does not (currently) work using the linker provided by nightly/beta Rust.
+    // See: https://github.com/dtolnay/linkme/pull/88,
+    //      https://blog.rust-lang.org/2024/05/17/enabling-rust-lld-on-linux.html
+    //
+    // This should eventually be fixed in linkme, making this code redundant:
+    // https://github.com/dtolnay/linkme/issues/94
+    //
+    // --niklasdewally
+    #[allow(clippy::unwrap_used)]
+    match version_meta().unwrap().channel {
+        Channel::Stable => {}
+        _ => {
+            println!("cargo::rustc-link-arg=-Wl,-z,nostart-stop-gc")
+        }
+    }
+}

crates/conjure_macros/Cargo.toml

@@ -6,6 +6,9 @@ edition = "2021"
 [lib]
 proc_macro = true
 
+[build-dependencies]
+rustc_version = "0.2"
+
 [dependencies]
 quote = "1.0.36"
 syn = { version = "2.0.60", features = ["full"] }

crates/conjure_macros/build.rs

@@ -0,0 +1,18 @@
+use rustc_version::{version_meta, Channel};
+fn main() {
+    // Linkme does not (currently) work using the linker provided by nightly/beta Rust.
+    // See: https://github.com/dtolnay/linkme/pull/88,
+    //      https://blog.rust-lang.org/2024/05/17/enabling-rust-lld-on-linux.html
+    //
+    // This should eventually be fixed in linkme, making this code redundant:
+    // https://github.com/dtolnay/linkme/issues/94
+    //
+    // --niklasdewally
+    #[allow(clippy::unwrap_used)]
+    match version_meta().unwrap().channel {
+        Channel::Stable => {}
+        _ => {
+            println!("cargo::rustc-link-arg=-Wl,-z,nostart-stop-gc")
+        }
+    }
+}