Fix invalid artifact directory when customizing target (#481)

# Objective

The Bevy CLI allows you to configure a custom compilation target in
`Cargo.toml`:

```toml
[package.metadata.bevy_cli.web]
target = "wasm32v1-none"
```

However, `bevy run web` doesn't work with this configuration, because it
searches for the Wasm binary in the `wasm32-unknown-unknown` target
folder.

# Solution

The cause of this problem is that we have to run the binary selection
_before_ loading the `Cargo.toml` config, to know which package to pull
the config from.
But the config can then alter the contents of the `BinTarget`, most
notably the `artifact_directory`.

As a fix, we run the bin target selection again after loading the
config, which fixes the problem.

# Testing

You can test via the [`no_std` package in the
bevy_complex_repo](https://github.com/TimJentzsch/bevy_complex_repo/tree/main/no_std).
It doesn't fully work yet, but at least it should compile now without an
error.

Author: TimJentzsch

src/bin_target.rs

@@ -16,6 +16,23 @@ pub struct BinTarget<'p> {
     pub bin_name: String,
 }
 
+impl BinTarget<'_> {
+    pub fn update_artifact_directory(
+        &mut self,
+        target_directory: impl Into<PathBuf>,
+        compile_target: Option<&str>,
+        compile_profile: &str,
+        is_example: bool,
+    ) {
+        self.artifact_directory = get_artifact_directory(
+            target_directory,
+            compile_target,
+            compile_profile,
+            is_example,
+        );
+    }
+}
+
 /// Determine which binary target should be run.
 ///
 /// The `--package` arg narrows down the search space to the given package,

src/build/mod.rs

@@ -16,7 +16,7 @@ pub mod args;
 pub fn build(args: &mut BuildArgs) -> anyhow::Result<()> {
     let metadata = cargo::metadata::metadata()?;
 
-    let bin_target = select_run_binary(
+    let mut bin_target = select_run_binary(
         &metadata,
         args.cargo_args.package_args.package.as_deref(),
         args.cargo_args.target_args.bin.as_deref(),
@@ -33,6 +33,13 @@ pub fn build(args: &mut BuildArgs) -> anyhow::Result<()> {
     )?;
 
     args.apply_config(&config);
+    // Update the artifact directory based on the config, e.g. in case the `target` changed
+    bin_target.update_artifact_directory(
+        &metadata.target_directory,
+        args.target().as_deref(),
+        args.profile(),
+        args.cargo_args.target_args.example.is_some(),
+    );
 
     #[cfg(feature = "web")]
     if args.is_web() {

src/run/mod.rs

@@ -16,7 +16,7 @@ pub mod args;
 pub fn run(args: &mut RunArgs) -> anyhow::Result<()> {
     let metadata = cargo::metadata::metadata()?;
 
-    let bin_target = select_run_binary(
+    let mut bin_target = select_run_binary(
         &metadata,
         args.cargo_args.package_args.package.as_deref(),
         args.cargo_args.target_args.bin.as_deref(),
@@ -32,6 +32,13 @@ pub fn run(args: &mut RunArgs) -> anyhow::Result<()> {
         args.is_release(),
     )?;
     args.apply_config(&config);
+    // Update the artifact directory based on the config, e.g. in case the `target` changed
+    bin_target.update_artifact_directory(
+        &metadata.target_directory,
+        args.target().as_deref(),
+        args.profile(),
+        args.cargo_args.target_args.example.is_some(),
+    );
 
     #[cfg(feature = "web")]
     if args.is_web() {