diff --git a/src/comm/comm.rs b/src/comm/comm.rs
index 749daa501..98f5b742b 100644
--- a/src/comm/comm.rs
+++ b/src/comm/comm.rs
@@ -65,9 +65,9 @@ fn comm(a: &mut LineReader, b: &mut LineReader, opts: &getopts::Matches) {
 
     let delim : Vec<String> = (0 .. 4).map(|col| mkdelim(col, opts)).collect();
 
-    let mut ra = &mut String::new();
+    let ra = &mut String::new();
     let mut na = a.read_line(ra);
-    let mut rb = &mut String::new();
+    let rb = &mut String::new();
     let mut nb = b.read_line(rb);
 
     while na.is_ok() || nb.is_ok() {
diff --git a/src/cp/cp.rs b/src/cp/cp.rs
index 1730ad43b..fc51df701 100644
--- a/src/cp/cp.rs
+++ b/src/cp/cp.rs
@@ -50,9 +50,6 @@ use std::fs::File;
 use std::fs::OpenOptions;
 use filetime::FileTime;
 
-#[cfg(target_os = "linux")]
-use libc::{c_int, c_char};
-
 #[cfg(unix)] use std::os::unix::fs::PermissionsExt;
 
 #[cfg(target_os = "linux")] ioctl!(write ficlone with 0x94, 9; std::os::raw::c_int);
@@ -681,16 +678,16 @@ fn preserve_hardlinks(hard_links: &mut Vec<(String, u64)>, source: &std::path::P
     if !source.is_dir() {
         unsafe {
             let src_path = CString::new(source.as_os_str().to_str().unwrap()).unwrap();
-            let mut inode: u64 = 0;
-            let mut nlinks = 0;
+            let inode: u64;
+            let nlinks: u64;
             #[cfg(unix)]
             {
                 let mut stat = mem::zeroed();
                 if libc::lstat(src_path.as_ptr(), &mut stat) < 0 {
                     return Err(format!("cannot stat {:?}: {}", src_path, std::io::Error::last_os_error()).into());
                 }
-                inode = stat.st_ino;
-                nlinks = stat.st_nlink;
+                inode = stat.st_ino as u64;
+                nlinks = stat.st_nlink as u64;
             }
             #[cfg(windows)]
             {
@@ -704,7 +701,7 @@ fn preserve_hardlinks(hard_links: &mut Vec<(String, u64)>, source: &std::path::P
                     return Err(format!("cannot get file information {:?}: {}", source, std::io::Error::last_os_error()).into());
                 }
                 inode = (((*stat).nFileIndexHigh as u64) << 32 | (*stat).nFileIndexLow as u64);
-                nlinks = (*stat).nNumberOfLinks;
+                nlinks = (*stat).nNumberOfLinks as u64;
             }
 
             for hard_link in hard_links.iter() {
@@ -750,7 +747,6 @@ fn copy(sources: &[Source], target: &Target, options: &Options) -> CopyResult<()
             let mut found_hard_link = false;
             if preserve_hard_links {
                     let dest = construct_dest_path(source, target, &target_type, options)?;
-                    let src_path = CString::new(Path::new(&source.clone()).as_os_str().to_str().unwrap()).unwrap();
                     preserve_hardlinks(&mut hard_links, source, dest, &mut found_hard_link).unwrap();
                }
             if !found_hard_link {
@@ -907,7 +903,7 @@ fn copy_attribute(source: &Path, dest: &Path, attribute: &Attribute) -> CopyResu
                let xattrs = xattr::list(source)?;
                for attr in xattrs {
                     if let Some(attr_value) = xattr::get(source, attr.clone())? {
-                        xattr::set(dest, attr, &attr_value[..]);
+                        crash_if_err!(EXIT_ERR, xattr::set(dest, attr, &attr_value[..]));
                     }
                }
             }
@@ -988,10 +984,14 @@ fn copy_file(source: &Path, dest: &Path, options: &Options) -> CopyResult<()> {
         println!("{}", context_for(source, dest));
     }
 
-    let mut preserve_context = false;
-    for attribute in &options.preserve_attributes {
-        if *attribute == Attribute::Context {
-            preserve_context = true;
+    #[allow(unused)]
+    {
+        // TODO: implement --preserve flag
+        let mut preserve_context = false;
+        for attribute in &options.preserve_attributes {
+            if *attribute == Attribute::Context {
+                preserve_context = true;
+            }
         }
     }
 
diff --git a/src/printf/tokenize/unescaped_text.rs b/src/printf/tokenize/unescaped_text.rs
index 45f006fdf..50eecc8ec 100644
--- a/src/printf/tokenize/unescaped_text.rs
+++ b/src/printf/tokenize/unescaped_text.rs
@@ -179,7 +179,7 @@ impl UnescapedText {
         let mut new_text = UnescapedText::new();
         let mut tmp_str = String::new();
         {
-            let mut new_vec: &mut Vec<u8> = &mut (new_text.0);
+            let new_vec: &mut Vec<u8> = &mut (new_text.0);
             while let Some(ch) = it.next() {
                 if !addchar {
                     addchar = true;
diff --git a/src/unexpand/unexpand.rs b/src/unexpand/unexpand.rs
index 556f97119..dbbe417bd 100644
--- a/src/unexpand/unexpand.rs
+++ b/src/unexpand/unexpand.rs
@@ -137,7 +137,7 @@ fn next_tabstop(tabstops: &[usize], col: usize) -> Option<usize> {
     }
 }
 
-fn write_tabs(mut output: &mut BufWriter<Stdout>, tabstops: &[usize],
+fn write_tabs(output: &mut BufWriter<Stdout>, tabstops: &[usize],
               mut scol: usize, col: usize, prevtab: bool, init: bool, amode: bool) {
     // This conditional establishes the following:
     // We never turn a single space before a non-blank into