Rollup of 4 pull requests

INSTALL.md

@@ -79,9 +79,23 @@ See [the rustc-dev-guide for more info][sysllvm].
    ./configure
    ```
 
-   If you plan to use `x.py install` to create an installation, it is
-   recommended that you set the `prefix` value in the `[install]` section to a
-   directory: `./configure --set install.prefix=<path>`
+   If you plan to use `x.py install` to create an installation, you can either
+   set `DESTDIR` environment variable to your custom directory path:
+
+   ```bash
+   export DESTDIR=<path>
+   ```
+
+   or set `prefix` and `sysconfdir` in the `[install]` section to your custom
+   directory path:
+
+   ```sh
+   ./configure --set install.prefix=<path> --set install.sysconfdir=<path>
+   ```
+
+   When the `DESTDIR` environment variable is present, the `prefix` and
+   `sysconfdir` values are combined with the path from the `DESTDIR`
+   environment variable.
 
 3. Build and install:
 

compiler/rustc_driver_impl/README.md

@@ -7,4 +7,4 @@ options).
 
 For more information about how the driver works, see the [rustc dev guide].
 
-[rustc dev guide]: https://rustc-dev-guide.rust-lang.org/rustc-driver.html
+[rustc dev guide]: https://rustc-dev-guide.rust-lang.org/rustc-driver/intro.html

library/core/src/intrinsics/mir.rs

@@ -213,7 +213,7 @@
 //!  - All other locals need to be declared with `let` somewhere and then can be accessed by name.
 //!
 //! #### Places
-//!  - Locals implicit convert to places.
+//!  - Locals implicitly convert to places.
 //!  - Field accesses, derefs, and indexing work normally.
 //!  - Fields in variants can be accessed via the [`Variant`] and [`Field`] associated functions,
 //!    see their documentation for details.

library/std/src/sys/pal/unix/thread.rs

@@ -117,13 +117,15 @@ impl Thread {
     pub fn set_name(name: &CStr) {
         const PR_SET_NAME: libc::c_int = 15;
         unsafe {
-            libc::prctl(
+            let res = libc::prctl(
                 PR_SET_NAME,
                 name.as_ptr(),
                 0 as libc::c_ulong,
                 0 as libc::c_ulong,
                 0 as libc::c_ulong,
             );
+            // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked.
+            debug_assert_eq!(res, 0);
         }
     }