diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index 82bd13475c7..0cdc71b6f60 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -73,7 +73,6 @@
 #![feature(unboxed_closures)]
 #![feature(unsafe_no_drop_flag)]
 #![feature(core)]
-#![feature(unique)]
 #![cfg_attr(test, feature(test, alloc, rustc_private))]
 #![cfg_attr(all(not(feature = "external_funcs"), not(feature = "external_crate")),
             feature(libc))]
diff --git a/src/libcollections/slice.rs b/src/libcollections/slice.rs
index a2924f8fe53..a9d6405a21b 100644
--- a/src/libcollections/slice.rs
+++ b/src/libcollections/slice.rs
@@ -2170,8 +2170,8 @@ mod tests {
     fn test_connect() {
         let v: [Vec<i32>; 0] = [];
         assert_eq!(v.connect(&0), []);
-        assert_eq!([vec![1i], vec![2, 3]].connect(&0), [1, 0, 2, 3]);
-        assert_eq!([vec![1i], vec![2], vec![3]].connect(&0), [1, 0, 2, 0, 3]);
+        assert_eq!([vec![1], vec![2, 3]].connect(&0), [1, 0, 2, 3]);
+        assert_eq!([vec![1], vec![2], vec![3]].connect(&0), [1, 0, 2, 0, 3]);
 
         let v: [&[_]; 2] = [&[1], &[2, 3]];
         assert_eq!(v.connect(&0), [1, 0, 2, 3]);
diff --git a/src/libcoretest/hash/mod.rs b/src/libcoretest/hash/mod.rs
index 9b6af182f72..14cd8ae45a6 100644
--- a/src/libcoretest/hash/mod.rs
+++ b/src/libcoretest/hash/mod.rs
@@ -85,7 +85,7 @@ struct CustomHasher { output: u64 }
 
 impl Hasher for CustomHasher {
     fn finish(&self) -> u64 { self.output }
-    fn write(&mut self, data: &[u8]) { panic!() }
+    fn write(&mut self, _: &[u8]) { panic!() }
     fn write_u64(&mut self, data: u64) { self.output = data; }
 }
 
diff --git a/src/libcoretest/str.rs b/src/libcoretest/str.rs
index 019f935911f..a89d3380707 100644
--- a/src/libcoretest/str.rs
+++ b/src/libcoretest/str.rs
@@ -188,15 +188,13 @@ fn trim_ws() {
 
 mod pattern {
     use std::str::Pattern;
-    use std::str::{Searcher, ReverseSearcher, DoubleEndedSearcher};
+    use std::str::{Searcher, ReverseSearcher};
     use std::str::SearchStep::{self, Match, Reject, Done};
 
     macro_rules! make_test {
         ($name:ident, $p:expr, $h:expr, [$($e:expr,)*]) => {
             mod $name {
-                use std::str::Pattern;
-                use std::str::{Searcher, ReverseSearcher, DoubleEndedSearcher};
-                use std::str::SearchStep::{self, Match, Reject, Done};
+                use std::str::SearchStep::{Match, Reject};
                 use super::{cmp_search_to_vec};
                 #[test]
                 fn fwd() {
diff --git a/src/librand/rand_impls.rs b/src/librand/rand_impls.rs
index d5c5d500465..dbba7bceeda 100644
--- a/src/librand/rand_impls.rs
+++ b/src/librand/rand_impls.rs
@@ -214,7 +214,6 @@ impl<T:Rand> Rand for Option<T> {
 
 #[cfg(test)]
 mod tests {
-    use std::prelude::v1::*;
     use std::rand::{Rng, thread_rng, Open01, Closed01};
 
     struct ConstantRng(u64);
diff --git a/src/librbml/io.rs b/src/librbml/io.rs
index c52465a8899..6d2da3d6c01 100644
--- a/src/librbml/io.rs
+++ b/src/librbml/io.rs
@@ -140,32 +140,32 @@ mod tests {
     fn test_seekable_mem_writer() {
         let mut writer = SeekableMemWriter::new();
         assert_eq!(writer.tell(), Ok(0));
-        writer.write(&[0]).unwrap();
+        writer.write_all(&[0]).unwrap();
         assert_eq!(writer.tell(), Ok(1));
-        writer.write(&[1, 2, 3]).unwrap();
-        writer.write(&[4, 5, 6, 7]).unwrap();
+        writer.write_all(&[1, 2, 3]).unwrap();
+        writer.write_all(&[4, 5, 6, 7]).unwrap();
         assert_eq!(writer.tell(), Ok(8));
         let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
         assert_eq!(writer.get_ref(), b);
 
         writer.seek(0, old_io::SeekSet).unwrap();
         assert_eq!(writer.tell(), Ok(0));
-        writer.write(&[3, 4]).unwrap();
+        writer.write_all(&[3, 4]).unwrap();
         let b: &[_] = &[3, 4, 2, 3, 4, 5, 6, 7];
         assert_eq!(writer.get_ref(), b);
 
         writer.seek(1, old_io::SeekCur).unwrap();
-        writer.write(&[0, 1]).unwrap();
+        writer.write_all(&[0, 1]).unwrap();
         let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 7];
         assert_eq!(writer.get_ref(), b);
 
         writer.seek(-1, old_io::SeekEnd).unwrap();
-        writer.write(&[1, 2]).unwrap();
+        writer.write_all(&[1, 2]).unwrap();
         let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 1, 2];
         assert_eq!(writer.get_ref(), b);
 
         writer.seek(1, old_io::SeekEnd).unwrap();
-        writer.write(&[1]).unwrap();
+        writer.write_all(&[1]).unwrap();
         let b: &[_] = &[3, 4, 2, 0, 1, 5, 6, 1, 2, 0, 1];
         assert_eq!(writer.get_ref(), b);
     }
@@ -174,7 +174,7 @@ mod tests {
     fn seek_past_end() {
         let mut r = SeekableMemWriter::new();
         r.seek(10, old_io::SeekSet).unwrap();
-        assert!(r.write(&[3]).is_ok());
+        assert!(r.write_all(&[3]).is_ok());
     }
 
     #[test]
@@ -190,7 +190,7 @@ mod tests {
         b.iter(|| {
             let mut wr = SeekableMemWriter::new();
             for _ in 0..times {
-                wr.write(&src).unwrap();
+                wr.write_all(&src).unwrap();
             }
 
             let v = wr.unwrap();
diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 69bcc82f682..c94edb9d2a1 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -422,15 +422,14 @@ mod tests {
     use prelude::v1::*;
     use super::*;
     use libc;
-    use mem;
 
     #[test]
     fn c_to_rust() {
         let data = b"123\0";
         let ptr = data.as_ptr() as *const libc::c_char;
         unsafe {
-            assert_eq!(c_str_to_bytes(&ptr), b"123");
-            assert_eq!(c_str_to_bytes_with_nul(&ptr), b"123\0");
+            assert_eq!(CStr::from_ptr(ptr).to_bytes(), b"123");
+            assert_eq!(CStr::from_ptr(ptr).to_bytes_with_nul(), b"123\0");
         }
     }
 
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index 3b4e15953c4..cf4eb09c19b 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -970,7 +970,7 @@ mod tests {
         struct R;
 
         impl Read for R {
-            fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+            fn read(&mut self, _: &mut [u8]) -> io::Result<usize> {
                 Err(io::Error::new(io::ErrorKind::Other, "", None))
             }
         }
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index b5bdeb7f181..de02b6af642 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -124,7 +124,7 @@
 #![feature(macro_reexport)]
 #![feature(hash)]
 #![feature(unique)]
-#![cfg_attr(test, feature(test, rustc_private, env))]
+#![cfg_attr(test, feature(test, rustc_private))]
 
 // Don't link to std. We are std.
 #![feature(no_std)]
diff --git a/src/libstd/process.rs b/src/libstd/process.rs
index c24b08deec2..3ed7daf4a0a 100644
--- a/src/libstd/process.rs
+++ b/src/libstd/process.rs
@@ -761,14 +761,13 @@ mod tests {
     #[cfg(not(target_os="android"))]
     #[test]
     fn test_inherit_env() {
-        use os;
+        use std::env;
         if running_on_valgrind() { return; }
 
         let result = env_cmd().output().unwrap();
         let output = String::from_utf8(result.stdout).unwrap();
 
-        let r = os::env();
-        for &(ref k, ref v) in &r {
+        for (ref k, ref v) in env::vars() {
             // don't check windows magical empty-named variables
             assert!(k.is_empty() ||
                     output.contains(format!("{}={}", *k, *v).as_slice()),
diff --git a/src/libterm/terminfo/searcher.rs b/src/libterm/terminfo/searcher.rs
index a0cd7842070..15f7f3884ec 100644
--- a/src/libterm/terminfo/searcher.rs
+++ b/src/libterm/terminfo/searcher.rs
@@ -96,7 +96,7 @@ pub fn open(term: &str) -> Result<File, String> {
 fn test_get_dbpath_for_term() {
     // woefully inadequate test coverage
     // note: current tests won't work with non-standard terminfo hierarchies (e.g. OS X's)
-    use std::os::{setenv, unsetenv};
+    use std::env;
     // FIXME (#9639): This needs to handle non-utf8 paths
     fn x(t: &str) -> String {
         let p = get_dbpath_for_term(t).expect("no terminfo entry found");
@@ -104,9 +104,9 @@ fn test_get_dbpath_for_term() {
     };
     assert!(x("screen") == "/usr/share/terminfo/s/screen");
     assert!(get_dbpath_for_term("") == None);
-    setenv("TERMINFO_DIRS", ":");
+    env::set_var("TERMINFO_DIRS", ":");
     assert!(x("screen") == "/usr/share/terminfo/s/screen");
-    unsetenv("TERMINFO_DIRS");
+    env::remove_var("TERMINFO_DIRS");
 }
 
 #[test]
diff --git a/src/libtest/lib.rs b/src/libtest/lib.rs
index a144904903e..3fbb07d03a8 100644
--- a/src/libtest/lib.rs
+++ b/src/libtest/lib.rs
@@ -732,8 +732,8 @@ fn should_sort_failures_before_printing_them() {
         Pretty(_) => unreachable!()
     };
 
-    let apos = s.find_str("a").unwrap();
-    let bpos = s.find_str("b").unwrap();
+    let apos = s.find("a").unwrap();
+    let bpos = s.find("b").unwrap();
     assert!(apos < bpos);
 }