Use edition 2018 idioms and warn when they are not followed

This was mostly automated using `cargo fix --edition-idioms`.

21 files changed, 48 insertions, 65 deletions

diff --git a/openssl/examples/mk_certs.rs b/openssl/examples/mk_certs.rs
index 5c9ec682..849cc4d2 100644
--- a/openssl/examples/mk_certs.rs
+++ b/openssl/examples/mk_certs.rs
@@ -1,8 +1,6 @@
 //! A program that generates ca certs, certs verified by the ca, and public
 //! and private keys.
 
-extern crate openssl;
-
 use openssl::asn1::Asn1Time;
 use openssl::bn::{BigNum, MsbOption};
 use openssl::error::ErrorStack;
diff --git a/openssl/src/asn1.rs b/openssl/src/asn1.rs
index 69f2026a..758a5d9d 100644
--- a/openssl/src/asn1.rs
+++ b/openssl/src/asn1.rs
@@ -65,7 +65,7 @@ foreign_type_and_impl_send_sync! {
 }
 
 impl fmt::Display for Asn1GeneralizedTimeRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         unsafe {
             let mem_bio = match MemBio::new() {
                 Err(_) => return f.write_str("error"),
@@ -284,7 +284,7 @@ impl<'a> PartialOrd<Asn1Time> for &'a Asn1TimeRef {
 }
 
 impl fmt::Display for Asn1TimeRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         unsafe {
             let mem_bio = match MemBio::new() {
                 Err(_) => return f.write_str("error"),
@@ -300,7 +300,7 @@ impl fmt::Display for Asn1TimeRef {
 }
 
 impl fmt::Debug for Asn1TimeRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(&self.to_string())
     }
 }
@@ -481,7 +481,7 @@ impl Asn1StringRef {
 }
 
 impl fmt::Debug for Asn1StringRef {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.as_utf8() {
             Ok(openssl_string) => openssl_string.fmt(fmt),
             Err(_) => fmt.write_str("error"),
@@ -636,7 +636,7 @@ impl Asn1ObjectRef {
 }
 
 impl fmt::Display for Asn1ObjectRef {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         unsafe {
             let mut buf = [0; 80];
             let len = ffi::OBJ_obj2txt(
@@ -654,7 +654,7 @@ impl fmt::Display for Asn1ObjectRef {
 }
 
 impl fmt::Debug for Asn1ObjectRef {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.write_str(self.to_string().as_str())
     }
 }
diff --git a/openssl/src/bn.rs b/openssl/src/bn.rs
index 4371e741..7a5484e3 100644
--- a/openssl/src/bn.rs
+++ b/openssl/src/bn.rs
@@ -1122,7 +1122,7 @@ impl BigNum {
 }
 
 impl fmt::Debug for BigNumRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.to_dec_str() {
             Ok(s) => f.write_str(&s),
             Err(e) => Err(e.into()),
@@ -1131,7 +1131,7 @@ impl fmt::Debug for BigNumRef {
 }
 
 impl fmt::Debug for BigNum {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.to_dec_str() {
             Ok(s) => f.write_str(&s),
             Err(e) => Err(e.into()),
@@ -1140,7 +1140,7 @@ impl fmt::Debug for BigNum {
 }
 
 impl fmt::Display for BigNumRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.to_dec_str() {
             Ok(s) => f.write_str(&s),
             Err(e) => Err(e.into()),
@@ -1149,7 +1149,7 @@ impl fmt::Display for BigNumRef {
 }
 
 impl fmt::Display for BigNum {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.to_dec_str() {
             Ok(s) => f.write_str(&s),
             Err(e) => Err(e.into()),
diff --git a/openssl/src/dsa.rs b/openssl/src/dsa.rs
index c58c6486..11fece79 100644
--- a/openssl/src/dsa.rs
+++ b/openssl/src/dsa.rs
@@ -288,7 +288,7 @@ impl Dsa<Public> {
 }
 
 impl<T> fmt::Debug for Dsa<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "DSA")
     }
 }
diff --git a/openssl/src/ec.rs b/openssl/src/ec.rs
index f43c8d3d..8218d65e 100644
--- a/openssl/src/ec.rs
+++ b/openssl/src/ec.rs
@@ -915,7 +915,7 @@ impl<T> Clone for EcKey<T> {
 }
 
 impl<T> fmt::Debug for EcKey<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "EcKey")
     }
 }
diff --git a/openssl/src/error.rs b/openssl/src/error.rs
index 55567e2b..0fc5d015 100644
--- a/openssl/src/error.rs
+++ b/openssl/src/error.rs
@@ -58,7 +58,7 @@ impl ErrorStack {
 }
 
 impl fmt::Display for ErrorStack {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         if self.0.is_empty() {
             return fmt.write_str("OpenSSL error");
         }
@@ -236,7 +236,7 @@ impl Error {
 }
 
 impl fmt::Debug for Error {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut builder = fmt.debug_struct("Error");
         builder.field("code", &self.code());
         if let Some(library) = self.library() {
@@ -258,7 +258,7 @@ impl fmt::Debug for Error {
 }
 
 impl fmt::Display for Error {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(fmt, "error:{:08X}", self.code())?;
         match self.library() {
             Some(l) => write!(fmt, ":{}", l)?,
diff --git a/openssl/src/hash.rs b/openssl/src/hash.rs
index c5c39a08..05f81019 100644
--- a/openssl/src/hash.rs
+++ b/openssl/src/hash.rs
@@ -390,7 +390,7 @@ impl AsRef<[u8]> for DigestBytes {
 }
 
 impl fmt::Debug for DigestBytes {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&**self, fmt)
     }
 }
diff --git a/openssl/src/lib.rs b/openssl/src/lib.rs
index 05c3eb8c..ca2cfc52 100644
--- a/openssl/src/lib.rs
+++ b/openssl/src/lib.rs
@@ -109,6 +109,7 @@
 //! ctx.set_ciphersuites("TLS_AES_256_GCM_SHA384:TLS_AES_128_GCM_SHA256").unwrap();
 //! ```
 #![doc(html_root_url = "https://docs.rs/openssl/0.10")]
+#![warn(rust_2018_idioms)]
 
 #[macro_use]
 extern crate bitflags;
@@ -116,14 +117,11 @@ extern crate bitflags;
 extern crate cfg_if;
 #[macro_use]
 extern crate foreign_types;
-extern crate libc;
-extern crate once_cell;
+
 extern crate openssl_sys as ffi;
 
 #[cfg(test)]
 extern crate hex;
-#[cfg(test)]
-extern crate tempdir;
 
 #[doc(inline)]
 pub use ffi::init;
diff --git a/openssl/src/pkcs12.rs b/openssl/src/pkcs12.rs
index b2764786..4e61d291 100644
--- a/openssl/src/pkcs12.rs
+++ b/openssl/src/pkcs12.rs
@@ -197,10 +197,8 @@ impl Pkcs12Builder {
 
 #[cfg(test)]
 mod test {
-    use crate::hash::MessageDigest;
-    use hex;
-
     use crate::asn1::Asn1Time;
+    use crate::hash::MessageDigest;
     use crate::nid::Nid;
     use crate::pkey::PKey;
     use crate::rsa::Rsa;
diff --git a/openssl/src/pkcs5.rs b/openssl/src/pkcs5.rs
index 6cc9609c..370db4da 100644
--- a/openssl/src/pkcs5.rs
+++ b/openssl/src/pkcs5.rs
@@ -281,8 +281,6 @@ mod tests {
     #[test]
     #[cfg(any(ossl110))]
     fn scrypt() {
-        use hex;
-
         let pass = "pleaseletmein";
         let salt = "SodiumChloride";
         let expected =
diff --git a/openssl/src/pkey.rs b/openssl/src/pkey.rs
index dcf941af..8c9c6999 100644
--- a/openssl/src/pkey.rs
+++ b/openssl/src/pkey.rs
@@ -292,7 +292,7 @@ where
 }
 
 impl<T> fmt::Debug for PKey<T> {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         let alg = match self.id() {
             Id::RSA => "RSA",
             Id::HMAC => "HMAC",
diff --git a/openssl/src/rsa.rs b/openssl/src/rsa.rs
index 446da6ab..8ff9965e 100644
--- a/openssl/src/rsa.rs
+++ b/openssl/src/rsa.rs
@@ -651,7 +651,7 @@ impl Rsa<Private> {
 }
 
 impl<T> fmt::Debug for Rsa<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "Rsa")
     }
 }
diff --git a/openssl/src/sha.rs b/openssl/src/sha.rs
index d6e69385..232ad856 100644
--- a/openssl/src/sha.rs
+++ b/openssl/src/sha.rs
@@ -341,8 +341,6 @@ impl Sha512 {
 
 #[cfg(test)]
 mod test {
-    use hex;
-
     use super::*;
 
     #[test]
diff --git a/openssl/src/ssl/error.rs b/openssl/src/ssl/error.rs
index 06cbb35e..5ec3e56a 100644
--- a/openssl/src/ssl/error.rs
+++ b/openssl/src/ssl/error.rs
@@ -99,7 +99,7 @@ impl From<ErrorStack> for Error {
 }
 
 impl fmt::Display for Error {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.code {
             ErrorCode::ZERO_RETURN => fmt.write_str("the SSL session has been shut down"),
             ErrorCode::WANT_READ => match self.io_error() {
@@ -157,7 +157,7 @@ impl<S: fmt::Debug> StdError for HandshakeError<S> {
 }
 
 impl<S: fmt::Debug> fmt::Display for HandshakeError<S> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             HandshakeError::SetupFailure(ref e) => write!(f, "stream setup failed: {}", e)?,
             HandshakeError::Failure(ref s) => {
diff --git a/openssl/src/ssl/mod.rs b/openssl/src/ssl/mod.rs
index 93a3bf0a..2328106c 100644
--- a/openssl/src/ssl/mod.rs
+++ b/openssl/src/ssl/mod.rs
@@ -1843,7 +1843,7 @@ impl ToOwned for SslContextRef {
 
 // TODO: add useful info here
 impl fmt::Debug for SslContext {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(fmt, "SslContext")
     }
 }
@@ -2346,7 +2346,7 @@ foreign_type_and_impl_send_sync! {
 }
 
 impl fmt::Debug for Ssl {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&**self, fmt)
     }
 }
@@ -2441,7 +2441,7 @@ impl Ssl {
 }
 
 impl fmt::Debug for SslRef {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.debug_struct("Ssl")
             .field("state", &self.state_string_long())
             .field("verify_result", &self.verify_result())
@@ -3469,7 +3469,7 @@ impl<S> fmt::Debug for SslStream<S>
 where
     S: fmt::Debug,
 {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.debug_struct("SslStream")
             .field("stream", &self.get_ref())
             .field("ssl", &self.ssl())
diff --git a/openssl/src/ssl/test/mod.rs b/openssl/src/ssl/test/mod.rs
index e145d22b..8d350224 100644
--- a/openssl/src/ssl/test/mod.rs
+++ b/openssl/src/ssl/test/mod.rs
@@ -1,6 +1,5 @@
 #![allow(unused_imports)]
 
-use hex;
 use std::env;
 use std::fs::File;
 use std::io::prelude::*;
@@ -1196,7 +1195,7 @@ fn stateless() {
             self.incoming.get_mut().extend_from_slice(data);
         }
 
-        pub fn take_outgoing(&mut self) -> Outgoing {
+        pub fn take_outgoing(&mut self) -> Outgoing<'_> {
             Outgoing(&mut self.outgoing)
         }
     }
diff --git a/openssl/src/stack.rs b/openssl/src/stack.rs
index b412029b..e5f32c77 100644
--- a/openssl/src/stack.rs
+++ b/openssl/src/stack.rs
@@ -50,7 +50,7 @@ where
     T: Stackable,
     T::Ref: fmt::Debug,
 {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.debug_list().entries(self).finish()
     }
 }
@@ -199,14 +199,14 @@ impl<T: Stackable> StackRef<T> {
         self.len() == 0
     }
 
-    pub fn iter(&self) -> Iter<T> {
+    pub fn iter(&self) -> Iter<'_, T> {
         Iter {
             stack: self,
             idxs: 0..self.len() as c_int,
         }
     }
 
-    pub fn iter_mut(&mut self) -> IterMut<T> {
+    pub fn iter_mut(&mut self) -> IterMut<'_, T> {
         IterMut {
             idxs: 0..self.len() as c_int,
             stack: self,
@@ -310,10 +310,7 @@ impl<'a, T: Stackable> iter::IntoIterator for &'a mut Stack<T> {
 }
 
 /// An iterator over the stack's contents.
-pub struct Iter<'a, T: Stackable>
-where
-    T: 'a,
-{
+pub struct Iter<'a, T: Stackable> {
     stack: &'a StackRef<T>,
     idxs: Range<c_int>,
 }
@@ -347,7 +344,7 @@ impl<'a, T: Stackable> DoubleEndedIterator for Iter<'a, T> {
 impl<'a, T: Stackable> ExactSizeIterator for Iter<'a, T> {}
 
 /// A mutable iterator over the stack's contents.
-pub struct IterMut<'a, T: Stackable + 'a> {
+pub struct IterMut<'a, T: Stackable> {
     stack: &'a mut StackRef<T>,
     idxs: Range<c_int>,
 }
diff --git a/openssl/src/string.rs b/openssl/src/string.rs
index f20e8434..5dd1f1ae 100644
--- a/openssl/src/string.rs
+++ b/openssl/src/string.rs
@@ -18,13 +18,13 @@ foreign_type_and_impl_send_sync! {
 }
 
 impl fmt::Display for OpensslString {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(&**self, f)
     }
 }
 
 impl fmt::Debug for OpensslString {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&**self, f)
     }
 }
@@ -69,13 +69,13 @@ impl AsRef<[u8]> for OpensslStringRef {
 }
 
 impl fmt::Display for OpensslStringRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(&**self, f)
     }
 }
 
 impl fmt::Debug for OpensslStringRef {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&**self, f)
     }
 }
diff --git a/openssl/src/x509/extension.rs b/openssl/src/x509/extension.rs
index dd4899c8..efe70f2b 100644
--- a/openssl/src/x509/extension.rs
+++ b/openssl/src/x509/extension.rs
@@ -397,7 +397,7 @@ impl SubjectKeyIdentifier {
     }
 
     /// Return a `SubjectKeyIdentifier` extension as an `X509Extension`.
-    pub fn build(&self, ctx: &X509v3Context) -> Result<X509Extension, ErrorStack> {
+    pub fn build(&self, ctx: &X509v3Context<'_>) -> Result<X509Extension, ErrorStack> {
         let mut value = String::new();
         let mut first = true;
         append(&mut value, &mut first, self.critical, "critical");
@@ -449,7 +449,7 @@ impl AuthorityKeyIdentifier {
     }
 
     /// Return a `AuthorityKeyIdentifier` extension as an `X509Extension`.
-    pub fn build(&self, ctx: &X509v3Context) -> Result<X509Extension, ErrorStack> {
+    pub fn build(&self, ctx: &X509v3Context<'_>) -> Result<X509Extension, ErrorStack> {
         let mut value = String::new();
         let mut first = true;
         append(&mut value, &mut first, self.critical, "critical");
@@ -538,7 +538,7 @@ impl SubjectAlternativeName {
     }
 
     /// Return a `SubjectAlternativeName` extension as an `X509Extension`.
-    pub fn build(&self, ctx: &X509v3Context) -> Result<X509Extension, ErrorStack> {
+    pub fn build(&self, ctx: &X509v3Context<'_>) -> Result<X509Extension, ErrorStack> {
         let mut value = String::new();
         let mut first = true;
         append(&mut value, &mut first, self.critical, "critical");
diff --git a/openssl/src/x509/mod.rs b/openssl/src/x509/mod.rs
index ad983fbd..b982be43 100644
--- a/openssl/src/x509/mod.rs
+++ b/openssl/src/x509/mod.rs
@@ -678,7 +678,7 @@ impl Clone for X509 {
 }
 
 impl fmt::Debug for X509 {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
         let serial = match &self.serial_number().to_bn() {
             Ok(bn) => match bn.to_hex_str() {
                 Ok(hex) => hex.to_string(),
@@ -749,7 +749,7 @@ impl X509Extension {
     /// See the extension module for builder types which will construct certain common extensions.
     pub fn new(
         conf: Option<&ConfRef>,
-        context: Option<&X509v3Context>,
+        context: Option<&X509v3Context<'_>>,
         name: &str,
         value: &str,
     ) -> Result<X509Extension, ErrorStack> {
@@ -775,7 +775,7 @@ impl X509Extension {
     /// See the extension module for builder types which will construct certain common extensions.
     pub fn new_nid(
         conf: Option<&ConfRef>,
-        context: Option<&X509v3Context>,
+        context: Option<&X509v3Context<'_>>,
         name: Nid,
         value: &str,
     ) -> Result<X509Extension, ErrorStack> {
@@ -956,7 +956,7 @@ impl X509NameRef {
 }
 
 impl fmt::Debug for X509NameRef {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
         formatter.debug_list().entries(self.entries()).finish()
     }
 }
@@ -1036,7 +1036,7 @@ impl X509NameEntryRef {
 }
 
 impl fmt::Debug for X509NameEntryRef {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
         formatter.write_fmt(format_args!("{:?} = {:?}", self.object(), self.data()))
     }
 }
@@ -1283,7 +1283,7 @@ impl X509ReqRef {
 pub struct X509VerifyResult(c_int);
 
 impl fmt::Debug for X509VerifyResult {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.debug_struct("X509VerifyResult")
             .field("code", &self.0)
             .field("error", &self.error_string())
@@ -1292,7 +1292,7 @@ impl fmt::Debug for X509VerifyResult {
 }
 
 impl fmt::Display for X509VerifyResult {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.write_str(self.error_string())
     }
 }
@@ -1397,7 +1397,7 @@ impl GeneralNameRef {
 }
 
 impl fmt::Debug for GeneralNameRef {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
         if let Some(email) = self.email() {
             formatter.write_str(email)
         } else if let Some(dnsname) = self.dnsname() {
diff --git a/systest/src/main.rs b/systest/src/main.rs
index 3e5888c8..cbfa3da6 100644
--- a/systest/src/main.rs
+++ b/systest/src/main.rs
@@ -1,8 +1,5 @@
 #![allow(bad_style, clippy::all)]
 
-extern crate libc;
-extern crate openssl_sys;
-
 use libc::*;
 use openssl_sys::*;