Support CI tests for old rust-gpu versions (#41)

Adds `rust-gpu` versions, `0.8.0` and `0.9.0` to the Linux matrix
on CI tests. `0.7.0` has a probably minor dependency error, but
it's also 18 months old and there probably aren't many users of it.

Notes:
* Adds a version arg to, eg: `cargo xtask --rust-gpu-version 0.8.0`.
* Offers a new CLI arg to workaround a bug where conflicting v3/v4
  versions of `Cargo.lock` files (between the shader and workspace)
  cause a build error. See `force_overwrite_lockfiles_v4_to_v3` arg.

Author: tombh

.github/workflows/push.yaml

@@ -19,6 +19,23 @@ jobs:
           - ubuntu-latest
           - macos-latest
           - windows-latest
+        rust-gpu-version: [latest]
+        include:
+          # As well as testing on each OS, we also want to test to make sure we're still supporting
+          # older versions of `rust-gpu`. However, we can assume that these tests are already okay
+          # across platforms, so we only need to test on Linux, the chepeast in terms of minutes.
+          #
+          # `0.7.0` currently fails building `spirv-builder-cli` with:
+          #    """
+          #    package `is_terminal_polyfill v1.70.1` cannot be built because it requires rustc 
+          #    1.70.0 or newer, while the currently active rustc version is 1.69.0-nightly
+          #    """
+          # It's probably easily fixable. But also `0.7.0` was released in April 2023, so there's
+          # unlikely many users of it?
+          - os: ubuntu-latest
+            rust-gpu-version: 0.8.0
+          - os: ubuntu-latest
+            rust-gpu-version: 0.9.0
     runs-on: ${{ matrix.os }}
     defaults:
       run:
@@ -35,9 +52,8 @@ jobs:
           rustup update
       - run: cargo test
       - name: Run a full build
-        run: cargo xtask test-build
+        run: cargo xtask test-build --rust-gpu-version ${{ matrix.rust-gpu-version }}
 
-
   lints:
     runs-on: ubuntu-latest
     steps:

.gitignore

@@ -20,3 +20,8 @@ flamegraph.svg
 
 # Compiled shader assets from running tests
 crates/shader-crate-template/shaders
+
+# Build artefacts used by CI tests
+tmp/*
+crates/shader-crate-template/manifest.json
+crates/shader-crate-template/rust_gpu_shader_crate_template.spv

Cargo.lock

@@ -23,6 +23,7 @@ toml.workspace = true
 chrono.workspace = true
 http.workspace = true
 crossterm.workspace = true
+version_check = "0.9.5"
 
 [dev-dependencies]
 test-log.workspace = true

crates/cargo-gpu/Cargo.toml

@@ -22,7 +22,7 @@ pub struct Build {
 
 impl Build {
     /// Entrypoint
-    #[expect(clippy::too_many_lines, reason = "these lines are fine")]
+    #[expect(clippy::too_many_lines, reason = "It's not too confusing")]
     pub fn run(&mut self) -> anyhow::Result<()> {
         let spirv_builder_cli_path = self.install.run()?;
 
@@ -150,7 +150,6 @@ impl Build {
             );
             std::fs::remove_file(spirv_manifest)?;
         }
-
         Ok(())
     }
 }

crates/cargo-gpu/src/build.rs

@@ -104,13 +104,14 @@ pub struct Install {
 
 impl Install {
     /// Returns a [`SpirvCLI`] instance, responsible for ensuring the right version of the `spirv-builder-cli` crate.
-    fn spirv_cli(&self, shader_crate_path: &std::path::PathBuf) -> anyhow::Result<SpirvCli> {
+    fn spirv_cli(&self, shader_crate_path: &std::path::Path) -> anyhow::Result<SpirvCli> {
         SpirvCli::new(
             shader_crate_path,
             self.spirv_install.spirv_builder_source.clone(),
             self.spirv_install.spirv_builder_version.clone(),
             self.spirv_install.rust_toolchain.clone(),
             self.spirv_install.auto_install_rust_toolchain,
+            self.spirv_install.force_overwrite_lockfiles_v4_to_v3,
         )
     }
 

crates/cargo-gpu/src/install.rs

@@ -134,7 +134,7 @@ fn run() -> anyhow::Result<()> {
                 "installing with final merged arguments: {:#?}",
                 command.install
             );
-            let _: std::path::PathBuf = command.install.run()?;
+            command.install.run()?;
         }
         Command::Build(build) => {
             let shader_crate_path = build.install.spirv_install.shader_crate;
@@ -150,7 +150,7 @@ fn run() -> anyhow::Result<()> {
                 command.run()?;
             } else {
                 command.run()?;
-            }
+            };
         }
         Command::Show(show) => show.run()?,
         Command::DumpUsage => dump_full_usage_for_readme()?,
@@ -274,6 +274,23 @@ mod test {
     use crate::cache_dir;
     use std::io::Write as _;
 
+    fn copy_dir_all(
+        src: impl AsRef<std::path::Path>,
+        dst: impl AsRef<std::path::Path>,
+    ) -> anyhow::Result<()> {
+        std::fs::create_dir_all(&dst)?;
+        for maybe_entry in std::fs::read_dir(src)? {
+            let entry = maybe_entry?;
+            let ty = entry.file_type()?;
+            if ty.is_dir() {
+                copy_dir_all(entry.path(), dst.as_ref().join(entry.file_name()))?;
+            } else {
+                std::fs::copy(entry.path(), dst.as_ref().join(entry.file_name()))?;
+            }
+        }
+        Ok(())
+    }
+
     pub fn shader_crate_template_path() -> std::path::PathBuf {
         let project_base = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
         project_base.join("../shader-crate-template")
@@ -304,21 +321,4 @@ mod test {
         }
         std::fs::remove_dir_all(cache_dir).unwrap();
     }
-
-    pub fn copy_dir_all(
-        src: impl AsRef<std::path::Path>,
-        dst: impl AsRef<std::path::Path>,
-    ) -> anyhow::Result<()> {
-        std::fs::create_dir_all(&dst)?;
-        for maybe_entry in std::fs::read_dir(src)? {
-            let entry = maybe_entry?;
-            let ty = entry.file_type()?;
-            if ty.is_dir() {
-                copy_dir_all(entry.path(), dst.as_ref().join(entry.file_name()))?;
-            } else {
-                std::fs::copy(entry.path(), dst.as_ref().join(entry.file_name()))?;
-            }
-        }
-        Ok(())
-    }
 }