feat(bidngen): we don't need to read stdout to know it will fail

src/bindgen.rs

@@ -69,29 +69,10 @@ pub fn wasm_bindgen_build(
         cmd.arg("--keep-debug");
     }
 
-    let result = child::run(cmd, "wasm-bindgen");
-    let result: Result<(), failure::Error> = match result {
-        Ok(r) => Ok(r),
-        Err(e) => process_error(&bindgen_path, e),
-    };
-    result.context("Running the wasm-bindgen CLI")?;
+    child::run(cmd, "wasm-bindgen").context("Running the wasm-bindgen CLI")?;
     Ok(())
 }
 
-fn process_error(bindgen_path: &PathBuf, e: child::CommandError) -> Result<(), failure::Error> {
-    match &e.stderr {
-        Some(err) if err.trim().starts_with("Unknown flag: '--web'") => {
-            let v = wasm_bindgen_get_version(bindgen_path).unwrap_or(String::from("unknown"));
-            bail!("Failed to execute `wasm-bindgen`: --web is not supported in version '{}'. Upgrade the wasm-bindgen dependency in Cargo.toml to version 0.2.39 or later.", v)
-        }
-        Some(err) => {
-            eprintln!("{}", err);
-            bail!("{}", e.to_string())
-        }
-        _ => bail!("{}", e.to_string()),
-    }
-}
-
 /// Check if the `wasm-bindgen` dependency is locally satisfied.
 fn wasm_bindgen_version_check(bindgen_path: &PathBuf, dep_version: &str) -> bool {
     wasm_bindgen_get_version(bindgen_path)

src/child.rs

@@ -3,6 +3,7 @@
 //! This module helps us ensure that all child processes that we spawn get
 //! properly logged and their output is logged as well.
 
+use failure::Error;
 use install::Tool;
 use log::info;
 use std::io::Error as StdError;
@@ -54,26 +55,19 @@ impl CommandError {
 }
 
 /// Run the given command and return on success.
-pub fn run(mut command: Command, command_name: &str) -> Result<(), CommandError> {
+pub fn run(mut command: Command, command_name: &str) -> Result<(), Error> {
     info!("Running {:?}", command);
 
-    let cmd_output = command
-        .stdin(Stdio::inherit())
-        .stdout(Stdio::inherit())
-        .output();
-    match cmd_output {
-        Ok(output) => {
-            if output.status.success() {
-                Ok(())
-            } else {
-                Err(CommandError::from_status(
-                    command_name,
-                    output.status,
-                    Some(String::from_utf8_lossy(&output.stderr).into_owned()),
-                ))
-            }
-        }
-        Err(e) => Err(CommandError::from_error(command_name, e)),
+    let status = command.status()?;
+
+    if status.success() {
+        Ok(())
+    } else {
+        bail!(
+            "failed to execute `{}`: exited with {}",
+            command_name,
+            status
+        )
     }
 }