diff --git a/src/libnative/io/process.rs b/src/libnative/io/process.rs
index 0b833f473955eaf7e22ac7a116c64b60d75bd7e1..6ac1f2b369244a3dacd51bd1ac58fc771769e297 100644
--- a/src/libnative/io/process.rs
+++ b/src/libnative/io/process.rs
@@ -470,7 +470,7 @@ unsafe fn set_cloexec(fd: c_int) {
                 Err(e) => {
                     assert!(e.kind == io::BrokenPipe ||
                             e.kind == io::EndOfFile,
-                            "unexpected error: {:?}", e);
+                            "unexpected error: {}", e);
                     Ok(SpawnProcessResult {
                         pid: pid,
                         handle: ptr::null()
@@ -744,7 +744,7 @@ pub fn WTERMSIG(status: i32) -> i32 { status & 0o177 }
 
         let mut status = 0 as c_int;
         match retry(|| unsafe { wait::waitpid(pid, &mut status, 0) }) {
-            -1 => fail!("unknown waitpid error: {:?}", super::last_error()),
+            -1 => fail!("unknown waitpid error: {}", super::last_error()),
             _ => {
                 if imp::WIFEXITED(status) {
                     p::ExitStatus(imp::WEXITSTATUS(status) as int)
diff --git a/src/libstd/num/strconv.rs b/src/libstd/num/strconv.rs
index 153c042c6a8c16acfa63ca875106cb25e2da4e6a..00497b6f0eaf06ffa0b66ceb06974a383e74fa2e 100644
--- a/src/libstd/num/strconv.rs
+++ b/src/libstd/num/strconv.rs
@@ -532,19 +532,19 @@ pub fn from_str_bytes_common<T:NumCast+Zero+One+Eq+Ord+Div<T,T>+
         ) -> Option<T> {
     match exponent {
         ExpDec if radix >= DIGIT_E_RADIX       // decimal exponent 'e'
-          => fail!("from_str_bytes_common: radix {:?} incompatible with \
+          => fail!("from_str_bytes_common: radix {} incompatible with \
                     use of 'e' as decimal exponent", radix),
         ExpBin if radix >= DIGIT_P_RADIX       // binary exponent 'p'
-          => fail!("from_str_bytes_common: radix {:?} incompatible with \
+          => fail!("from_str_bytes_common: radix {} incompatible with \
                     use of 'p' as binary exponent", radix),
         _ if special && radix >= DIGIT_I_RADIX // first digit of 'inf'
-          => fail!("from_str_bytes_common: radix {:?} incompatible with \
+          => fail!("from_str_bytes_common: radix {} incompatible with \
                     special values 'inf' and 'NaN'", radix),
         _ if (radix as int) < 2
-          => fail!("from_str_bytes_common: radix {:?} to low, \
+          => fail!("from_str_bytes_common: radix {} to low, \
                     must lie in the range [2, 36]", radix),
         _ if (radix as int) > 36
-          => fail!("from_str_bytes_common: radix {:?} to high, \
+          => fail!("from_str_bytes_common: radix {} to high, \
                     must lie in the range [2, 36]", radix),
         _ => ()
     }