diff --git a/src/libextra/base64.rs b/src/libextra/base64.rs
index f4754b3e4cb..5bf4dd517a5 100644
--- a/src/libextra/base64.rs
+++ b/src/libextra/base64.rs
@@ -229,8 +229,6 @@ impl<'self> FromBase64 for &'self str {
 
 #[cfg(test)]
 mod tests {
-    use core::str;
-
     #[test]
     fn test_to_base64() {
         assert_eq!("".to_base64(), ~"");
diff --git a/src/libextra/rope.rs b/src/libextra/rope.rs
index 12539cd4759..fed73256c00 100644
--- a/src/libextra/rope.rs
+++ b/src/libextra/rope.rs
@@ -1271,7 +1271,6 @@ mod tests {
 
     use rope::*;
 
-    use core::str;
     use core::uint;
     use core::vec;
 
diff --git a/src/libextra/sha1.rs b/src/libextra/sha1.rs
index 908e497b959..38cb1471154 100644
--- a/src/libextra/sha1.rs
+++ b/src/libextra/sha1.rs
@@ -24,7 +24,6 @@
 
 use core::prelude::*;
 
-use core::str;
 use core::uint;
 use core::vec;
 
@@ -279,8 +278,6 @@ pub fn sha1() -> @Sha1 {
 mod tests {
     use sha1;
 
-    use core::vec;
-
     #[test]
     fn test() {
         struct Test {
diff --git a/src/libextra/smallintmap.rs b/src/libextra/smallintmap.rs
index 7f566bc16e7..d63e1c4516f 100644
--- a/src/libextra/smallintmap.rs
+++ b/src/libextra/smallintmap.rs
@@ -294,11 +294,6 @@ mod tests {
 
     use super::SmallIntMap;
 
-    use core::local_data;
-    use core::rand;
-    use core::uint;
-    use core::vec;
-
     #[test]
     fn test_find_mut() {
         let mut m = SmallIntMap::new();
diff --git a/src/libextra/sort.rs b/src/libextra/sort.rs
index 0189e0db6d4..b88fd374da2 100644
--- a/src/libextra/sort.rs
+++ b/src/libextra/sort.rs
@@ -751,7 +751,6 @@ fn shift_vec<T:Copy>(dest: &mut [T],
 mod test_qsort3 {
     use sort::*;
 
-    use core::vec;
 
     fn check_sort(v1: &mut [int], v2: &mut [int]) {
         let len = v1.len();
@@ -861,8 +860,6 @@ mod tests {
 
     use sort::*;
 
-    use core::vec;
-
     fn check_sort(v1: &[int], v2: &[int]) {
         let len = v1.len();
         pub fn le(a: &int, b: &int) -> bool { *a <= *b }
diff --git a/src/libextra/stats.rs b/src/libextra/stats.rs
index 4af47fa806f..3a1de5de01d 100644
--- a/src/libextra/stats.rs
+++ b/src/libextra/stats.rs
@@ -12,7 +12,6 @@
 
 use core::prelude::*;
 
-use core::vec;
 use core::f64;
 use core::cmp;
 use core::num;
diff --git a/src/libextra/std.rc b/src/libextra/std.rc
index 83c0bb516b4..93759bea35f 100644
--- a/src/libextra/std.rc
+++ b/src/libextra/std.rc
@@ -37,6 +37,7 @@ not required in or otherwise suitable for the core library.
 
 extern mod core(name = "std", vers = "0.7-pre");
 
+#[cfg(stage0)]
 use core::{str, unstable};
 use core::str::{StrSlice, OwnedStr};
 
diff --git a/src/libextra/tempfile.rs b/src/libextra/tempfile.rs
index c239e65e2d9..39dcee5eff3 100644
--- a/src/libextra/tempfile.rs
+++ b/src/libextra/tempfile.rs
@@ -36,7 +36,6 @@ mod tests {
     use tempfile::mkdtemp;
 
     use core::os;
-    use core::str;
 
     #[test]
     fn test_mkdtemp() {
diff --git a/src/libextra/terminfo/parser/compiled.rs b/src/libextra/terminfo/parser/compiled.rs
index 81b6083db01..66649c62fca 100644
--- a/src/libextra/terminfo/parser/compiled.rs
+++ b/src/libextra/terminfo/parser/compiled.rs
@@ -313,7 +313,6 @@ pub fn parse(file: @Reader, longnames: bool) -> Result<~TermInfo, ~str> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use p = core::path::Path;
 
     #[test]
     fn test_veclens() {
diff --git a/src/libextra/treemap.rs b/src/libextra/treemap.rs
index f98758f64af..e37ce7c71ef 100644
--- a/src/libextra/treemap.rs
+++ b/src/libextra/treemap.rs
@@ -710,7 +710,6 @@ mod test_treemap {
 
     use core::rand::RngUtil;
     use core::rand;
-    use core::str;
     use core::vec;
 
     #[test]
diff --git a/src/librustc/back/rpath.rs b/src/librustc/back/rpath.rs
index 85fc0575170..33f578d335b 100644
--- a/src/librustc/back/rpath.rs
+++ b/src/librustc/back/rpath.rs
@@ -199,9 +199,6 @@ pub fn minimize_rpaths(rpaths: &[Path]) -> ~[Path] {
 mod test {
     use core::prelude::*;
 
-    use core::os;
-    use core::str;
-
     // FIXME(#2119): the outer attribute should be #[cfg(unix, test)], then
     // these redundant #[cfg(test)] blocks can be removed
     #[cfg(test)]
diff --git a/src/librustc/middle/astencode.rs b/src/librustc/middle/astencode.rs
index e11367a7a7d..925b1f506d7 100644
--- a/src/librustc/middle/astencode.rs
+++ b/src/librustc/middle/astencode.rs
@@ -15,7 +15,6 @@ use cstore = metadata::cstore;
 use driver::session::Session;
 use e = metadata::encoder;
 use metadata::decoder;
-use metadata::encoder;
 use metadata::tydecode;
 use metadata::tydecode::{DefIdSource, NominalType, TypeWithId, TypeParameter};
 use metadata::tyencode;
diff --git a/src/librustc/middle/trans/adt.rs b/src/librustc/middle/trans/adt.rs
index ad07f41f8c3..09db79037b3 100644
--- a/src/librustc/middle/trans/adt.rs
+++ b/src/librustc/middle/trans/adt.rs
@@ -47,7 +47,6 @@
 use core::container::Map;
 use core::libc::c_ulonglong;
 use core::option::{Option, Some, None};
-use core::str;
 use core::vec;
 
 use lib::llvm::{ValueRef, TypeRef, True, IntEQ, IntNE};
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index e2073d21fe3..ffc54bbed35 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -71,7 +71,6 @@ use core::libc::c_uint;
 use core::str;
 use core::uint;
 use core::vec;
-use core::local_data;
 use extra::time;
 use syntax::ast::ident;
 use syntax::ast_map::{path, path_elt_to_str, path_name};
@@ -3120,4 +3119,3 @@ pub fn trans_crate(sess: session::Session,
 
     return (llcx, llmod, link_meta);
 }
-
diff --git a/src/librustdoc/desc_to_brief_pass.rs b/src/librustdoc/desc_to_brief_pass.rs
index dc7621f98a0..dbaa5e8532c 100644
--- a/src/librustdoc/desc_to_brief_pass.rs
+++ b/src/librustdoc/desc_to_brief_pass.rs
@@ -24,7 +24,6 @@ use fold::Fold;
 use fold;
 use pass::Pass;
 
-use core::str;
 use core::util;
 
 pub fn mk_pass() -> Pass {
diff --git a/src/librustdoc/markdown_pass.rs b/src/librustdoc/markdown_pass.rs
index 36df3a5267d..075b64a674c 100644
--- a/src/librustdoc/markdown_pass.rs
+++ b/src/librustdoc/markdown_pass.rs
@@ -22,7 +22,6 @@ use markdown_writer::WriterFactory;
 use pass::Pass;
 use sort_pass;
 
-use core::iterator::IteratorUtil;
 use core::cell::Cell;
 use core::str;
 use core::vec;
diff --git a/src/librustdoc/text_pass.rs b/src/librustdoc/text_pass.rs
index 1f7a71e0fd8..6db582a60e9 100644
--- a/src/librustdoc/text_pass.rs
+++ b/src/librustdoc/text_pass.rs
@@ -149,8 +149,6 @@ mod test {
     use sectionalize_pass;
     use text_pass::mk_pass;
 
-    use core::str;
-
     fn mk_doc(source: ~str) -> doc::Doc {
         do astsrv::from_str(copy source) |srv| {
             let doc = extract::from_srv(srv.clone(), ~"");
diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index 99a7a461ab2..9c4e8f08358 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -947,7 +947,6 @@ pub mod windows {
 mod tests {
     use option::{None, Some};
     use path::{PosixPath, WindowsPath, windows};
-    use str;
 
     #[test]
     fn test_double_slash_collapsing() {
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 25166eca7bb..44e480dc7df 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -39,8 +39,6 @@ pub mod rt {
     use parse;
     use print::pprust;
 
-    use core::str;
-
     pub use ast::*;
     pub use parse::token::*;
     pub use parse::new_parser_from_tts;
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 035675e523e..c1bf979cd31 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -969,7 +969,7 @@ mod test {
     // change every identifier to "zz"
     pub fn to_zz() -> @fn(ast::ident)->ast::ident {
         let zz_id = token::str_to_ident("zz");
-        |id| {zz_id}
+        |_id| {zz_id}
     }
 
     // maybe add to expand.rs...