solidity: various small resolc fixes (#189)

crates/solidity/src/solc/combined_json/mod.rs

@@ -80,10 +80,9 @@ impl CombinedJson {
         file_path.push(format!("combined.{}", revive_common::EXTENSION_JSON));
 
         if file_path.exists() && !overwrite {
-            eprintln!(
+            anyhow::bail!(
                 "Refusing to overwrite an existing file {file_path:?} (use --overwrite to force)."
             );
-            return Ok(());
         }
 
         File::create(&file_path)

crates/solidity/src/solc/solc_compiler.rs

@@ -152,8 +152,16 @@ impl Compiler for SolcCompiler {
             anyhow::anyhow!("{} subprocess error: {:?}", self.executable, error)
         })?;
         if !output.status.success() {
-            println!("{}", String::from_utf8_lossy(output.stdout.as_slice()));
-            println!("{}", String::from_utf8_lossy(output.stderr.as_slice()));
+            writeln!(
+                std::io::stdout(),
+                "{}",
+                String::from_utf8_lossy(output.stdout.as_slice())
+            )?;
+            writeln!(
+                std::io::stdout(),
+                "{}",
+                String::from_utf8_lossy(output.stderr.as_slice())
+            )?;
             anyhow::bail!(
                 "{} error: {}",
                 self.executable,

crates/solidity/src/solc/standard_json/input/mod.rs

@@ -68,12 +68,8 @@ impl Input {
             paths.insert(PathBuf::from(library_file));
         }
 
-        #[cfg(feature = "parallel")]
-        let iter = paths.into_par_iter(); // Parallel iterator
-        #[cfg(not(feature = "parallel"))]
-        let iter = paths.iter(); // Sequential iterator
-
-        let sources = iter
+        let sources = paths
+            .iter()
             .map(|path| {
                 let source = Source::try_from(path.as_path()).unwrap_or_else(|error| {
                     panic!("Source code file {path:?} reading error: {error}")