diff --git a/Cargo.lock b/Cargo.lock
index d47afb51b2..1ddfdcce47 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -26,27 +26,6 @@ dependencies = [
  "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "backtrace"
-version = "0.3.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "backtrace-sys 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
- "cfg-if 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-demangle 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
- "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "backtrace-sys"
-version = "0.1.28"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "cc 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "bindgen"
 version = "0.51.1"
@@ -66,7 +45,7 @@ dependencies = [
  "regex 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "shlex 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "which 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "which 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -138,14 +117,6 @@ dependencies = [
  "termcolor 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "failure"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "glob"
 version = "0.2.11"
@@ -266,11 +237,6 @@ dependencies = [
  "ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "rustc-demangle"
-version = "0.1.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "rustc-hash"
 version = "1.0.1"
@@ -355,10 +321,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "which"
-version = "2.0.1"
+version = "3.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -402,8 +367,6 @@ dependencies = [
 "checksum aho-corasick 0.6.8 (registry+https://github.com/rust-lang/crates.io-index)" = "68f56c7353e5a9547cbd76ed90f7bb5ffc3ba09d4ea9bd1d8c06c8b1142eeb5a"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
-"checksum backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)" = "18b65ea1161bfb2dd6da6fade5edd4dbd08fba85012123dd333d2fd1b90b2782"
-"checksum backtrace-sys 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)" = "797c830ac25ccc92a7f8a7b9862bde440715531514594a6154e3d4a54dd769b6"
 "checksum bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "228047a76f468627ca71776ecdebd732a3423081fcf5125585bcd7c49886ce12"
 "checksum byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "94f88df23a25417badc922ab0f5716cc1330e87f71ddd9203b3a3ccd9cedf75d"
 "checksum cc 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)" = "f159dfd43363c4d08055a07703eb7a3406b0dac4d0584d96965a3262db3c9d16"
@@ -413,7 +376,6 @@ dependencies = [
 "checksum clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b957d88f4b6a63b9d70d5f454ac8011819c6efa7727858f458ab71c756ce2d3e"
 "checksum diff 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "3c2b69f912779fbb121ceb775d74d51e915af17aaebc38d28a592843a2dd0a3a"
 "checksum env_logger 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "afb070faf94c85d17d50ca44f6ad076bce18ae92f0037d350947240a36e9d42e"
-"checksum failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "795bd83d3abeb9220f257e597aa0080a508b27533824adf336529648f6abf7e2"
 "checksum glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "8be18de09a56b60ed0edf84bc9df007e30040691af7acd1c41874faac5895bfb"
 "checksum humantime 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0484fda3e7007f2a4a0d9c3a703ca38c71c54c55602ce4660c419fd32e188c9e"
 "checksum lazy_static 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca488b89a5657b0a2ecd45b95609b3e848cf1755da332a0da46e2b2b1cb371a7"
@@ -430,7 +392,6 @@ dependencies = [
 "checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
 "checksum regex 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "2069749032ea3ec200ca51e4a31df41759190a88edca0d2d86ee8bedf7073341"
 "checksum regex-syntax 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "747ba3b235651f6e2f67dfa8bcdcd073ddb7c243cb21c442fc12395dfcac212d"
-"checksum rustc-demangle 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "ccc78bfd5acd7bf3e89cffcf899e5cb1a52d6fafa8dec2739ad70c9577a57288"
 "checksum rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7540fc8b0c49f096ee9c961cda096467dce8084bec6bdca2fc83895fd9b28cb8"
 "checksum shlex 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7fdf1b9db47230893d76faad238fd6097fd6d6a9245cd7a4d90dbd639536bbd2"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
@@ -444,7 +405,7 @@ dependencies = [
 "checksum utf8-ranges 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "fd70f467df6810094968e2fce0ee1bd0e87157aceb026a8c083bcf5e25b9efe4"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
 "checksum version_check 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7716c242968ee87e5542f8021178248f267f295a5c4803beae8b8b7fd9bc6051"
-"checksum which 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b57acb10231b9493c8472b20cb57317d0679a49e0bdbee44b3b803a6473af164"
+"checksum which 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "240a31163872f7e8e49f35b42b58485e35355b07eb009d9f3686733541339a69"
 "checksum winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "773ef9dcc5f24b7d850d0ff101e542ff24c3b090a9768e03ff889fdef41f00fd"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 "checksum winapi-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "afc5508759c5bf4285e61feb862b6083c8480aec864fa17a81fdec6f69b461ab"
diff --git a/Cargo.toml b/Cargo.toml
index 64658af254..fabb6ae4ed 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -54,7 +54,7 @@ lazy_static = "1"
 peeking_take_while = "0.1.2"
 quote = { version = "1", default-features = false }
 regex = "1.0"
-which = { version = ">=1.0, <3.0", optional = true }
+which = { version = "3.0", optional = true, default-features = false }
 shlex = "0.1"
 rustc-hash = "1.0.1"
 # New validation in 0.3.6 breaks bindgen-integration: