diff --git a/src/libextra/test.rs b/src/libextra/test.rs
index 7400973c28a..4721a6b4122 100644
--- a/src/libextra/test.rs
+++ b/src/libextra/test.rs
@@ -30,7 +30,6 @@ use treemap::TreeMap;
 
 use std::clone::Clone;
 use std::comm::{stream, SharedChan, GenericPort, GenericChan};
-use std::libc;
 use std::io;
 use std::result;
 use std::task;
@@ -125,8 +124,9 @@ pub type MetricDiff = TreeMap<~str,MetricChange>;
 pub fn test_main(args: &[~str], tests: ~[TestDescAndFn]) {
     let opts =
         match parse_opts(args) {
-            Ok(o) => o,
-            Err(msg) => fail!(msg)
+            Some(Ok(o)) => o,
+            Some(Err(msg)) => fail!(msg),
+            None => return
         };
     if !run_tests_console(&opts, tests) { fail!("Some tests failed"); }
 }
@@ -189,7 +189,7 @@ fn optgroups() -> ~[getopts::groups::OptGroup] {
                      "A.B")]
 }
 
-fn usage(binary: &str, helpstr: &str) -> ! {
+fn usage(binary: &str, helpstr: &str) {
     #[fixed_stack_segment]; #[inline(never)];
 
     let message = fmt!("Usage: %s [OPTIONS] [FILTER]", binary);
@@ -217,20 +217,19 @@ Test Attributes:
                      tests. This may also be written as #[ignore(cfg(...))] to
                      ignore the test on certain configurations.");
     }
-    unsafe { libc::exit(0) }
 }
 
 // Parses command line arguments into test options
-pub fn parse_opts(args: &[~str]) -> OptRes {
+pub fn parse_opts(args: &[~str]) -> Option<OptRes> {
     let args_ = args.tail();
     let matches =
         match groups::getopts(args_, optgroups()) {
           Ok(m) => m,
-          Err(f) => return Err(f.to_err_msg())
+          Err(f) => return Some(Err(f.to_err_msg()))
         };
 
-    if matches.opt_present("h") { usage(args[0], "h"); }
-    if matches.opt_present("help") { usage(args[0], "help"); }
+    if matches.opt_present("h") { usage(args[0], "h"); return None; }
+    if matches.opt_present("help") { usage(args[0], "help"); return None; }
 
     let filter =
         if matches.free.len() > 0 {
@@ -272,7 +271,7 @@ pub fn parse_opts(args: &[~str]) -> OptRes {
         logfile: logfile
     };
 
-    Ok(test_opts)
+    Some(Ok(test_opts))
 }
 
 pub fn opt_shard(maybestr: Option<~str>) -> Option<(uint,uint)> {
@@ -1228,7 +1227,7 @@ mod tests {
     fn first_free_arg_should_be_a_filter() {
         let args = ~[~"progname", ~"filter"];
         let opts = match parse_opts(args) {
-            Ok(o) => o,
+            Some(Ok(o)) => o,
             _ => fail!("Malformed arg in first_free_arg_should_be_a_filter")
         };
         assert!("filter" == opts.filter.clone().unwrap());
@@ -1238,7 +1237,7 @@ mod tests {
     fn parse_ignored_flag() {
         let args = ~[~"progname", ~"filter", ~"--ignored"];
         let opts = match parse_opts(args) {
-            Ok(o) => o,
+            Some(Ok(o)) => o,
             _ => fail!("Malformed arg in parse_ignored_flag")
         };
         assert!((opts.run_ignored));
diff --git a/src/librust/rust.rs b/src/librust/rust.rs
index 00c4afef587..6ebce51b29f 100644
--- a/src/librust/rust.rs
+++ b/src/librust/rust.rs
@@ -44,7 +44,7 @@ impl ValidUsage {
 
 enum Action {
     Call(extern "Rust" fn(args: &[~str]) -> ValidUsage),
-    CallMain(&'static str, extern "Rust" fn(&[~str])),
+    CallMain(&'static str, extern "Rust" fn(&[~str]) -> int),
 }
 
 enum UsageSource<'self> {
@@ -185,18 +185,17 @@ fn cmd_run(args: &[~str]) -> ValidUsage {
     }
 }
 
-fn invoke(prog: &str, args: &[~str], f: &fn(&[~str])) {
+fn invoke(prog: &str, args: &[~str], f: &fn(&[~str]) -> int) -> int {
     let mut osargs = ~[prog.to_owned()];
     osargs.push_all_move(args.to_owned());
-    f(osargs);
+    f(osargs)
 }
 
 fn do_command(command: &Command, args: &[~str]) -> ValidUsage {
     match command.action {
         Call(f) => f(args),
         CallMain(prog, f) => {
-            invoke(prog, args, f);
-            Valid(0)
+            Valid(invoke(prog, args, f))
         }
     }
 }
diff --git a/src/librustc/rustc.rs b/src/librustc/rustc.rs
index f1f7a7bf2d6..7599de1a9a3 100644
--- a/src/librustc/rustc.rs
+++ b/src/librustc/rustc.rs
@@ -394,13 +394,14 @@ pub fn monitor(f: ~fn(@diagnostic::Emitter)) {
 }
 
 pub fn main() {
-    let args = os::args();
-    main_args(args);
+    std::os::set_exit_status(main_args(std::os::args()));
 }
 
-pub fn main_args(args: &[~str]) {
+pub fn main_args(args: &[~str]) -> int {
     let owned_args = args.to_owned();
     do monitor |demitter| {
         run_compiler(owned_args, demitter);
     }
+
+    return 0;
 }
diff --git a/src/librustdoc/rustdoc.rs b/src/librustdoc/rustdoc.rs
index bc7e6c8926d..c3d8cdf028e 100644
--- a/src/librustdoc/rustdoc.rs
+++ b/src/librustdoc/rustdoc.rs
@@ -52,7 +52,7 @@ enum OutputFormat {
 }
 
 pub fn main() {
-    main_args(std::os::args());
+    std::os::set_exit_status(main_args(std::os::args()));
 }
 
 pub fn opts() -> ~[groups::OptGroup] {
@@ -76,14 +76,14 @@ pub fn usage(argv0: &str) {
                                   argv0), opts()));
 }
 
-pub fn main_args(args: &[~str]) {
+pub fn main_args(args: &[~str]) -> int {
     //use extra::getopts::groups::*;
 
     let matches = groups::getopts(args.tail(), opts()).unwrap();
 
     if matches.opt_present("h") || matches.opt_present("help") {
         usage(args[0]);
-        return;
+        return 0;
     }
 
     let (format, cratefile) = match matches.free.clone() {
@@ -92,17 +92,17 @@ pub fn main_args(args: &[~str]) {
         [s, _] => {
             println!("Unknown output format: `{}`", s);
             usage(args[0]);
-            exit(1);
+            return 1;
         }
         [_, .._] => {
             println!("Expected exactly one crate to process");
             usage(args[0]);
-            exit(1);
+            return 1;
         }
         _ => {
             println!("Expected an output format and then one crate");
             usage(args[0]);
-            exit(1);
+            return 1;
         }
     };
 
@@ -179,6 +179,8 @@ pub fn main_args(args: &[~str]) {
     }
     let ended = time::precise_time_ns();
     info2!("Took {:.03f}s", (ended as f64 - started as f64) / 1000000000f64);
+
+    return 0;
 }
 
 fn jsonify(crate: clean::Crate, res: ~[plugins::PluginJson], dst: Path) {
@@ -208,9 +210,3 @@ fn jsonify(crate: clean::Crate, res: ~[plugins::PluginJson], dst: Path) {
     let output = extra::json::Object(json).to_str();
     file.write(output.as_bytes());
 }
-
-fn exit(status: int) -> ! {
-    #[fixed_stack_segment]; #[inline(never)];
-    use std::libc;
-    unsafe { libc::exit(status as libc::c_int) }
-}
diff --git a/src/librusti/rusti.rs b/src/librusti/rusti.rs
index 462c0a29236..eb94a112dd1 100644
--- a/src/librusti/rusti.rs
+++ b/src/librusti/rusti.rs
@@ -517,8 +517,7 @@ pub fn run_line(repl: &mut Repl, input: @io::Reader, out: @io::Writer, line: ~st
 }
 
 pub fn main() {
-    let args = os::args();
-    main_args(args);
+    os::set_exit_status(main_args(os::args()));
 }
 
 struct Completer;
@@ -534,7 +533,7 @@ impl CompletionCb for Completer {
     }
 }
 
-pub fn main_args(args: &[~str]) {
+pub fn main_args(args: &[~str]) -> int {
     #[fixed_stack_segment]; #[inline(never)];
 
     let input = io::stdin();
@@ -576,6 +575,8 @@ pub fn main_args(args: &[~str]) {
             }
         }
     }
+
+    return 0;
 }
 
 #[cfg(test)]
diff --git a/src/librustpkg/rustpkg.rs b/src/librustpkg/rustpkg.rs
index 25d0802b9ad..c10ea2fb424 100644
--- a/src/librustpkg/rustpkg.rs
+++ b/src/librustpkg/rustpkg.rs
@@ -615,11 +615,10 @@ impl CtxMethods for BuildContext {
 
 pub fn main() {
     io::println("WARNING: The Rust package manager is experimental and may be unstable");
-    let args = os::args();
-    main_args(args);
+    os::set_exit_status(main_args(os::args()));
 }
 
-pub fn main_args(args: &[~str]) {
+pub fn main_args(args: &[~str]) -> int {
     let opts = ~[getopts::optflag("h"), getopts::optflag("help"),
                                         getopts::optflag("no-link"),
                                         getopts::optflag("no-trans"),
@@ -645,7 +644,7 @@ pub fn main_args(args: &[~str]) {
         result::Err(f) => {
             error(fmt!("%s", f.to_err_msg()));
 
-            return;
+            return 1;
         }
     };
     let mut help = matches.opt_present("h") ||
@@ -662,7 +661,7 @@ pub fn main_args(args: &[~str]) {
     if matches.opt_present("v") ||
        matches.opt_present("version") {
         rustc::version(args[0]);
-        return;
+        return 0;
     }
 
     let use_rust_path_hack = matches.opt_present("r") ||
@@ -701,7 +700,8 @@ pub fn main_args(args: &[~str]) {
     args.shift();
 
     if (args.len() < 1) {
-        return usage::general();
+        usage::general();
+        return 1;
     }
 
     let rustc_flags = RustcFlags {
@@ -739,11 +739,14 @@ pub fn main_args(args: &[~str]) {
         }
     }
     let cmd = match cmd_opt {
-        None => return usage::general(),
+        None => {
+            usage::general();
+            return 0;
+        }
         Some(cmd) => {
             help |= context::flags_ok_for_cmd(&rustc_flags, cfgs, *cmd, user_supplied_opt_level);
             if help {
-                return match *cmd {
+                match *cmd {
                     ~"build" => usage::build(),
                     ~"clean" => usage::clean(),
                     ~"do" => usage::do_cmd(),
@@ -757,6 +760,7 @@ pub fn main_args(args: &[~str]) {
                     ~"unprefer" => usage::unprefer(),
                     _ => usage::general()
                 };
+                return 0;
             } else {
                 cmd
             }
@@ -794,8 +798,8 @@ pub fn main_args(args: &[~str]) {
     // and at least one test case succeeds if rustpkg returns COPY_FAILED_CODE,
     // when actually, it might set the exit code for that even if a different
     // unhandled condition got raised.
-    if result.is_err() { os::set_exit_status(COPY_FAILED_CODE); }
-
+    if result.is_err() { return COPY_FAILED_CODE; }
+    return 0;
 }
 
 /**