diff --git a/rust-version b/rust-version
index 6c876993b7..e00bba6867 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-06a079c43efb062e335e6e6c9dabd3c750619980
+b5c9e2448c9ace53ad5c11585803894651b18b0a
diff --git a/src/helpers.rs b/src/helpers.rs
index 23bc54e76b..a13d9b4519 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -387,7 +387,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     /// if this is not the case.
     fn assert_target_os(&self, target_os: &str, name: &str) {
         assert_eq!(
-            self.eval_context_ref().tcx.sess.target.target.target_os,
+            self.eval_context_ref().tcx.sess.target.target_os,
             target_os,
             "`{}` is only available on the `{}` target OS",
             name,
@@ -430,7 +430,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     fn set_last_error_from_io_error(&mut self, e: std::io::Error) -> InterpResult<'tcx> {
         use std::io::ErrorKind::*;
         let this = self.eval_context_mut();
-        let target = &this.tcx.sess.target.target;
+        let target = &this.tcx.sess.target;
         let target_os = &target.target_os;
         let last_error = if target.options.target_family == Some("unix".to_owned()) {
             this.eval_libc(match e.kind() {
diff --git a/src/machine.rs b/src/machine.rs
index 6defb2d053..544f4667e8 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -173,7 +173,7 @@ impl MemoryExtra {
     pub fn init_extern_statics<'tcx, 'mir>(
         this: &mut MiriEvalContext<'mir, 'tcx>,
     ) -> InterpResult<'tcx> {
-        match this.tcx.sess.target.target.target_os.as_str() {
+        match this.tcx.sess.target.target_os.as_str() {
             "linux" => {
                 // "__cxa_thread_atexit_impl"
                 // This should be all-zero, pointer-sized.
diff --git a/src/shims/env.rs b/src/shims/env.rs
index 42fd6e3dce..2db64ad5a1 100644
--- a/src/shims/env.rs
+++ b/src/shims/env.rs
@@ -38,7 +38,7 @@ impl<'tcx> EnvVars<'tcx> {
         ecx: &mut InterpCx<'mir, 'tcx, Evaluator<'mir, 'tcx>>,
         mut excluded_env_vars: Vec<String>,
     ) -> InterpResult<'tcx> {
-        let target_os = ecx.tcx.sess.target.target.target_os.as_str();
+        let target_os = ecx.tcx.sess.target.target_os.as_str();
         if target_os == "windows" {
             // Temporary hack: Exclude `TERM` var to avoid terminfo trying to open the termcap file.
             // Can be removed once https://github.com/rust-lang/miri/issues/1013 is resolved.
@@ -101,7 +101,7 @@ impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mi
 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
     fn getenv(&mut self, name_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, Scalar<Tag>> {
         let this = self.eval_context_mut();
-        let target_os = &this.tcx.sess.target.target.target_os;
+        let target_os = &this.tcx.sess.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`getenv` is only available for the UNIX target family");
 
         let name_ptr = this.read_scalar(name_op)?.check_init()?;
@@ -185,7 +185,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         value_op: OpTy<'tcx, Tag>,
     ) -> InterpResult<'tcx, i32> {
         let mut this = self.eval_context_mut();
-        let target_os = &this.tcx.sess.target.target.target_os;
+        let target_os = &this.tcx.sess.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`setenv` is only available for the UNIX target family");
 
         let name_ptr = this.read_scalar(name_op)?.check_init()?;
@@ -258,7 +258,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
 
     fn unsetenv(&mut self, name_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
         let this = self.eval_context_mut();
-        let target_os = &this.tcx.sess.target.target.target_os;
+        let target_os = &this.tcx.sess.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`unsetenv` is only available for the UNIX target family");
 
         let name_ptr = this.read_scalar(name_op)?.check_init()?;
@@ -290,7 +290,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         size_op: OpTy<'tcx, Tag>,
     ) -> InterpResult<'tcx, Scalar<Tag>> {
         let this = self.eval_context_mut();
-        let target_os = &this.tcx.sess.target.target.target_os;
+        let target_os = &this.tcx.sess.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`getcwd` is only available for the UNIX target family");
 
         this.check_no_isolation("`getcwd`")?;
@@ -336,7 +336,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
 
     fn chdir(&mut self, path_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
         let this = self.eval_context_mut();
-        let target_os = &this.tcx.sess.target.target.target_os;
+        let target_os = &this.tcx.sess.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`getcwd` is only available for the UNIX target family");
 
         this.check_no_isolation("`chdir`")?;
diff --git a/src/shims/foreign_items.rs b/src/shims/foreign_items.rs
index 7118fbda24..cd6024444f 100644
--- a/src/shims/foreign_items.rs
+++ b/src/shims/foreign_items.rs
@@ -19,7 +19,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     fn min_align(&self, size: u64, kind: MiriMemoryKind) -> Align {
         let this = self.eval_context_ref();
         // List taken from `libstd/sys_common/alloc.rs`.
-        let min_align = match this.tcx.sess.target.target.arch.as_str() {
+        let min_align = match this.tcx.sess.target.arch.as_str() {
             "x86" | "arm" | "mips" | "powerpc" | "powerpc64" | "asmjs" | "wasm32" => 8,
             "x86_64" | "aarch64" | "mips64" | "s390x" | "sparc64" => 16,
             arch => bug!("Unsupported target architecture: {}", arch),
@@ -480,13 +480,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             }
 
             // Architecture-specific shims
-            "llvm.x86.sse2.pause" if this.tcx.sess.target.target.arch == "x86" || this.tcx.sess.target.target.arch == "x86_64" => {
+            "llvm.x86.sse2.pause" if this.tcx.sess.target.arch == "x86" || this.tcx.sess.target.arch == "x86_64" => {
                 let &[] = check_arg_count(args)?;
                 this.yield_active_thread();
             }
 
             // Platform-specific shims
-            _ => match this.tcx.sess.target.target.target_os.as_str() {
+            _ => match this.tcx.sess.target.target_os.as_str() {
                 "linux" | "macos" => return shims::posix::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest, ret),
                 "windows" => return shims::windows::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest, ret),
                 target => throw_unsup_format!("the target `{}` is not supported", target),
diff --git a/src/shims/os_str.rs b/src/shims/os_str.rs
index 7635047064..268b0902e9 100644
--- a/src/shims/os_str.rs
+++ b/src/shims/os_str.rs
@@ -234,7 +234,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         direction: PathConversion,
     ) -> Cow<'a, OsStr> {
         let this = self.eval_context_ref();
-        let target_os = &this.tcx.sess.target.target.target_os;
+        let target_os = &this.tcx.sess.target.target_os;
         #[cfg(windows)]
         return if target_os == "windows" {
             // Windows-on-Windows, all fine.
diff --git a/src/shims/posix/foreign_items.rs b/src/shims/posix/foreign_items.rs
index 177678f03d..c527fa0d06 100644
--- a/src/shims/posix/foreign_items.rs
+++ b/src/shims/posix/foreign_items.rs
@@ -165,7 +165,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 this.read_scalar(handle)?.to_machine_usize(this)?;
                 let symbol = this.read_scalar(symbol)?.check_init()?;
                 let symbol_name = this.memory.read_c_str(symbol)?;
-                if let Some(dlsym) = Dlsym::from_str(symbol_name, &this.tcx.sess.target.target.target_os)? {
+                if let Some(dlsym) = Dlsym::from_str(symbol_name, &this.tcx.sess.target.target_os)? {
                     let ptr = this.memory.create_fn_alloc(FnVal::Other(dlsym));
                     this.write_scalar(Scalar::from(ptr), dest)?;
                 } else {
@@ -452,7 +452,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
 
             // Platform-specific shims
             _ => {
-                match this.tcx.sess.target.target.target_os.as_str() {
+                match this.tcx.sess.target.target_os.as_str() {
                     "linux" => return shims::posix::linux::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest, ret),
                     "macos" => return shims::posix::macos::foreign_items::EvalContextExt::emulate_foreign_item_by_name(this, link_name, args, dest, ret),
                     _ => unreachable!(),
diff --git a/src/shims/posix/fs.rs b/src/shims/posix/fs.rs
index ebf7e16a15..a9d102912a 100644
--- a/src/shims/posix/fs.rs
+++ b/src/shims/posix/fs.rs
@@ -555,7 +555,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 },
                 None => return this.handle_not_found(),
             }
-        } else if this.tcx.sess.target.target.target_os == "macos"
+        } else if this.tcx.sess.target.target_os == "macos"
             && cmd == this.eval_libc_i32("F_FULLFSYNC")?
         {
             let &[_, _] = check_arg_count(args)?;
@@ -989,7 +989,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         this.check_no_isolation("`mkdir`")?;
 
         #[cfg_attr(not(unix), allow(unused_variables))]
-        let mode = if this.tcx.sess.target.target.target_os == "macos" {
+        let mode = if this.tcx.sess.target.target_os == "macos" {
             u32::from(this.read_scalar(mode_op)?.check_init()?.to_u16()?)
         } else {
             this.read_scalar(mode_op)?.to_u32()?
diff --git a/src/shims/posix/linux/dlsym.rs b/src/shims/posix/linux/dlsym.rs
index 9be300edf4..af5f5a20e4 100644
--- a/src/shims/posix/linux/dlsym.rs
+++ b/src/shims/posix/linux/dlsym.rs
@@ -27,7 +27,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
         let (_dest, _ret) = ret.expect("we don't support any diverging dlsym");
-        assert!(this.tcx.sess.target.target.target_os == "linux");
+        assert!(this.tcx.sess.target.target_os == "linux");
 
         match dlsym {}
     }
diff --git a/src/shims/posix/macos/dlsym.rs b/src/shims/posix/macos/dlsym.rs
index c9f57090ff..82d8b16ad6 100644
--- a/src/shims/posix/macos/dlsym.rs
+++ b/src/shims/posix/macos/dlsym.rs
@@ -32,7 +32,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
         let (dest, ret) = ret.expect("we don't support any diverging dlsym");
-        assert!(this.tcx.sess.target.target.target_os == "macos");
+        assert!(this.tcx.sess.target.target_os == "macos");
 
         match dlsym {
             Dlsym::getentropy => {
diff --git a/src/shims/tls.rs b/src/shims/tls.rs
index 2ba0782f70..7b4d8fa56a 100644
--- a/src/shims/tls.rs
+++ b/src/shims/tls.rs
@@ -340,7 +340,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             // This is the first time we got asked to schedule a destructor. The
             // Windows schedule destructor function must be called exactly once,
             // this is why it is in this block.
-            if this.tcx.sess.target.target.target_os == "windows" {
+            if this.tcx.sess.target.target_os == "windows" {
                 // On Windows, we signal that the thread quit by starting the
                 // relevant function, reenabling the thread, and going back to
                 // the scheduler.
diff --git a/src/shims/windows/dlsym.rs b/src/shims/windows/dlsym.rs
index 91bfedff8d..5454a00f14 100644
--- a/src/shims/windows/dlsym.rs
+++ b/src/shims/windows/dlsym.rs
@@ -44,7 +44,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
         let (dest, ret) = ret.expect("we don't support any diverging dlsym");
-        assert!(this.tcx.sess.target.target.target_os == "windows");
+        assert!(this.tcx.sess.target.target_os == "windows");
 
         match dlsym {
             Dlsym::AcquireSRWLockExclusive => {
diff --git a/src/shims/windows/foreign_items.rs b/src/shims/windows/foreign_items.rs
index fc1093b64f..d141fa57e1 100644
--- a/src/shims/windows/foreign_items.rs
+++ b/src/shims/windows/foreign_items.rs
@@ -213,7 +213,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 let &[hModule, lpProcName] = check_arg_count(args)?;
                 this.read_scalar(hModule)?.to_machine_isize(this)?;
                 let name = this.memory.read_c_str(this.read_scalar(lpProcName)?.check_init()?)?;
-                if let Some(dlsym) = Dlsym::from_str(name, &this.tcx.sess.target.target.target_os)? {
+                if let Some(dlsym) = Dlsym::from_str(name, &this.tcx.sess.target.target_os)? {
                     let ptr = this.memory.create_fn_alloc(FnVal::Other(dlsym));
                     this.write_scalar(Scalar::from(ptr), dest)?;
                 } else {