From 73369f32621f6a844a80a8513ae3ded901e4a406 Mon Sep 17 00:00:00 2001

From: Mark Rousskov <mark.simulacrum@gmail.com>

Date: Tue, 5 Nov 2019 11:16:46 -0500

Subject: [PATCH] Hopefully fix rustdoc build

It's super unclear why this broke when we switched to beta but not

previously -- but at least it's hopefully fixed now.

---

 src/bootstrap/builder.rs | 13 ++++++++++++-

 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs

index 2748903f2d47..2edcef203ad2 100644

--- a/src/bootstrap/builder.rs

+++ b/src/bootstrap/builder.rs

@@ -886,7 +886,18 @@ impl<'a> Builder<'a> {

         // things still build right, please do!

         match mode {

             Mode::Std => metadata.push_str("std"),

-            _ => {},

+            // When we're building rustc tools, they're built with a search path

+            // that contains things built during the rustc build. For example,

+            // bitflags is built during the rustc build, and is a dependency of

+            // rustdoc as well. We're building rustdoc in a different target

+            // directory, though, which means that Cargo will rebuild the

+            // dependency. When we go on to build rustdoc, we'll look for

+            // bitflags, and find two different copies: one built during the

+            // rustc step and one that we just built. This isn't always a

+            // problem, somehow -- not really clear why -- but we know that this

+            // fixes things.

+            Mode::ToolRustc => metadata.push_str("tool-rustc"),

+            _ => {}

         }

         cargo.env("__CARGO_DEFAULT_LIB_METADATA", &metadata);

-- 

2.23.0