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From:   Trevor Gross <tmgross@umich.edu>
To:     ojeda@kernel.org, alex.gaynor@gmail.com, wedsonaf@gmail.com
Cc:     boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com,
        benno.lossin@proton.me, corbet@lwn.net, yakoyoku@gmail.com,
        aliceryhl@google.com, tmgross@umich.edu, linux-doc@vger.kernel.org,
        rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/2] docs: rust: update instructions for obtaining 'core' source
Date:   Thu,  3 Aug 2023 02:04:36 -0400
Message-Id: <20230803060437.12157-2-tmgross@umich.edu>
In-Reply-To: <20230803060437.12157-1-tmgross@umich.edu>
References: <20230803060437.12157-1-tmgross@umich.edu>
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The source for Rust's 'core' library is needed to build the kernel with
Rust support. This sometimes needs to be obtained by hand when using a
standalone version of 'rustc' not managed by 'rustup'. Currently, the
documentation suggests cloning the 'rust' repository to obtain these
sources, but this is quite slow (on the order of a multiple minutes).

Change this documentation to suggest using the source tarball instead.
The tarball includes only needed files (<5M) and is significantly faster
to download; this is more in line with what 'rustup' does.

Also simplify wording of the relevant section.

Link: https://github.com/Rust-for-Linux/linux/pull/1024
Signed-off-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
---
 Documentation/rust/quick-start.rst | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/Documentation/rust/quick-start.rst b/Documentation/rust/quick-start.rst
index a8931512ed98..632b115dd20d 100644
--- a/Documentation/rust/quick-start.rst
+++ b/Documentation/rust/quick-start.rst
@@ -56,16 +56,17 @@ If ``rustup`` is being used, run::
 The components are installed per toolchain, thus upgrading the Rust compiler
 version later on requires re-adding the component.
 
-Otherwise, if a standalone installer is used, the Rust repository may be cloned
-into the installation folder of the toolchain::
+Otherwise, if a standalone installer is used, the Rust source tree may be
+downloaded into the toolchain's installation folder::
 
-	git clone --recurse-submodules \
-		--branch $(scripts/min-tool-version.sh rustc) \
-		https://github.com/rust-lang/rust \
-		$(rustc --print sysroot)/lib/rustlib/src/rust
+	curl -L "https://static.rust-lang.org/dist/rust-src-$(scripts/min-tool-version.sh rustc).tar.gz" |
+		tar -xzf - -C "$(rustc --print sysroot)/lib" \
+		"rust-src-$(scripts/min-tool-version.sh rustc)/rust-src/lib/" \
+		--strip-components=3
 
 In this case, upgrading the Rust compiler version later on requires manually
-updating this clone.
+updating the source tree (this can be done by removing ``$(rustc --print
+sysroot)/lib/rustlib/src/rust`` then rerunning the above command).
 
 
 libclang
-- 
2.34.1