Set CARGO_TARGET_DIR when using Flycheck custom command

Author: Tyrubias

crates/flycheck/src/lib.rs

@@ -58,6 +58,7 @@ pub enum FlycheckConfig {
         extra_env: FxHashMap<String, String>,
         invocation_strategy: InvocationStrategy,
         invocation_location: InvocationLocation,
+        target_dir: Option<PathBuf>,
     },
 }
 
@@ -354,10 +355,15 @@ impl FlycheckActor {
                 extra_env,
                 invocation_strategy,
                 invocation_location,
+                target_dir,
             } => {
                 let mut cmd = Command::new(command);
                 cmd.envs(extra_env);
 
+                if let Some(target_dir) = target_dir {
+                    cmd.env("CARGO_TARGET_DIR", target_dir);
+                }
+
                 match invocation_location {
                     InvocationLocation::Workspace => {
                         match invocation_strategy {

crates/rust-analyzer/src/config.rs

@@ -1289,6 +1289,7 @@ impl Config {
     }
 
     pub fn flycheck(&self) -> FlycheckConfig {
+        let target_dir = self.target_dir_from_config();
         match &self.data.check_overrideCommand {
             Some(args) if !args.is_empty() => {
                 let mut args = args.clone();
@@ -1309,6 +1310,7 @@ impl Config {
                         }
                         InvocationLocation::Workspace => flycheck::InvocationLocation::Workspace,
                     },
+                    target_dir,
                 }
             }
             Some(_) | None => FlycheckConfig::CargoCommand {
@@ -1343,7 +1345,7 @@ impl Config {
                 extra_args: self.check_extra_args(),
                 extra_env: self.check_extra_env(),
                 ansi_color_output: self.color_diagnostic_output(),
-                target_dir: self.target_dir_from_config(),
+                target_dir,
             },
         }
     }