Add a shared library building test

.github/workflows/CI.yml

@@ -43,6 +43,8 @@ jobs:
           rustup target add aarch64-unknown-linux-gnu
           cargo run zigbuild --target aarch64-unknown-linux-gnu
           cargo run zigbuild --target aarch64-unknown-linux-gnu.2.17
+          # Test building shared library
+          cargo run zigbuild --target aarch64-unknown-linux-gnu --manifest-path tests/libhello/Cargo.toml
       - name: Linux - Test musl libc build
         run: |
           rustup target add aarch64-unknown-linux-musl

.gitignore

@@ -1 +1 @@
-/target
+target/

src/cli.rs

@@ -327,7 +327,11 @@ impl Build {
                 let target_dir = self
                     .target_dir
                     .clone()
-                    .or_else(|| self.manifest_path.as_ref().map(|m| m.join("target")))
+                    .or_else(|| {
+                        self.manifest_path
+                            .as_ref()
+                            .map(|m| m.parent().unwrap().join("target"))
+                    })
                     .unwrap_or_else(|| {
                         env::current_dir()
                             .expect("Failed to get current working directory")

tests/libhello/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "hello"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]

tests/libhello/src/lib.rs

@@ -0,0 +1,4 @@
+#[no_mangle]
+pub extern "C" fn hello() {
+    println!("hello");
+}