2 files changed, 7 insertions, 5 deletions
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 35ada678740..ad005833ad5 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -174,7 +174,9 @@
 //!
 //! - after-main use of thread-locals, which also affects additional features:
 //!   - [`thread::current()`]
-//! - before-main stdio file descriptors are not guaranteed to be open on unix platforms
+//! - under UNIX, before main, file descriptors 0, 1, and 2 may be unchanged
+//!   (they are guaranteed to be open during main,
+//!    and are opened to /dev/null O_RDWR if they weren't open on program start)
 //!
 //!
 //! [I/O]: io
diff --git a/library/std/src/macros.rs b/library/std/src/macros.rs
index e0f9f0bb5ce..f008d42804c 100644
--- a/library/std/src/macros.rs
+++ b/library/std/src/macros.rs
@@ -41,7 +41,7 @@ macro_rules! panic {
 /// Use `print!` only for the primary output of your program. Use
 /// [`eprint!`] instead to print error and progress messages.
 ///
-/// See [the formatting documentation in `std::fmt`](../std/fmt/index.html)
+/// See the formatting documentation in [`std::fmt`](crate::fmt)
 /// for details of the macro argument syntax.
 ///
 /// [flush]: crate::io::Write::flush
@@ -106,7 +106,7 @@ macro_rules! print {
 /// Use `println!` only for the primary output of your program. Use
 /// [`eprintln!`] instead to print error and progress messages.
 ///
-/// See [the formatting documentation in `std::fmt`](../std/fmt/index.html)
+/// See the formatting documentation in [`std::fmt`](crate::fmt)
 /// for details of the macro argument syntax.
 ///
 /// [`std::fmt`]: crate::fmt
@@ -156,7 +156,7 @@ macro_rules! println {
 /// [`io::stderr`]: crate::io::stderr
 /// [`io::stdout`]: crate::io::stdout
 ///
-/// See [the formatting documentation in `std::fmt`](../std/fmt/index.html)
+/// See the formatting documentation in [`std::fmt`](crate::fmt)
 /// for details of the macro argument syntax.
 ///
 /// # Panics
@@ -190,7 +190,7 @@ macro_rules! eprint {
 /// Use `eprintln!` only for error and progress messages. Use `println!`
 /// instead for the primary output of your program.
 ///
-/// See [the formatting documentation in `std::fmt`](../std/fmt/index.html)
+/// See the formatting documentation in [`std::fmt`](crate::fmt)
 /// for details of the macro argument syntax.
 ///
 /// [`io::stderr`]: crate::io::stderr