[PATCH v2] rust: Avoid passing host-specific information to crates Strict Version Hash

[PATCH v2] rust: Avoid passing host-specific information to crates Strict Version Hash

[Alejandro Hernandez]

rustc computes each crate's Strict Version Hash (SVH) using inputs that include
the *stage0/stage1 bootstrap compiler* fingerprint, which in turn depends on the
build host arch.

This eventually may cause sstate matches across architectures for artifacts that
are actually different, causing autobuilder intermitent reproducibility issues.

To avoid this, pass a fixed value instead of host-specific bits to the specified
hash.

[YOCTO #15554]

Assisted-by: AI - OpenAI
Signed-off-by: Alejandro Hernandez <alhe@linux.microsoft.com>
---
 ...ide-cfg-version-from-stable-crate-id.patch | 20 +++++++++++++++++++
 meta/recipes-devtools/rust/rust-source.inc    |  1 +
 2 files changed, 21 insertions(+)
 create mode 100644 meta/recipes-devtools/rust/files/0003-rustc-span-add-oe-knob-to-elide-cfg-version-from-stable-crate-id.patch

diff --git a/meta/recipes-devtools/rust/files/0003-rustc-span-add-oe-knob-to-elide-cfg-version-from-stable-crate-id.patch b/meta/recipes-devtools/rust/files/0003-rustc-span-add-oe-knob-to-elide-cfg-version-from-stable-crate-id.patch
new file mode 100644
index 0000000000..8409d49bbe
--- /dev/null
+++ b/meta/recipes-devtools/rust/files/0003-rustc-span-add-oe-knob-to-elide-cfg-version-from-stable-crate-id.patch
@@ -0,0 +1,20 @@
+rust: Avoid passing host-dependent fingerprint to build artifacts
+
+To fix reproducibility issues, pass a fixed value instead of passing a
+host-dependent fingerprint to the rust build artifacts via the Strict
+Version Hash (SVH)
+
+Upstream-Status: Inappropriate [OE-specific reproducibility policy]
+Signed-off-by: Alejandro Hernandez <alhe@linux.microsoft.com>
+---
+--- a/compiler/rustc_span/src/def_id.rs
++++ b/compiler/rustc_span/src/def_id.rs
+@@ -186,5 +186,3 @@
+-        if let Some(val) = std::env::var_os("RUSTC_FORCE_RUSTC_VERSION") {
+-            hasher.write(val.to_string_lossy().into_owned().as_bytes())
+-        } else {
+-            hasher.write(cfg_version.as_bytes())
+-        }
++        // OE reproducible builds use a fixed value so host-varying bootstrap
++        // fingerprints do not perturb StableCrateId.
++        hasher.write(b"oe-stable-crate-id-no-cfg-version")
diff --git a/meta/recipes-devtools/rust/rust-source.inc b/meta/recipes-devtools/rust/rust-source.inc
index 68f3009a7b..2bff69de3d 100644
--- a/meta/recipes-devtools/rust/rust-source.inc
+++ b/meta/recipes-devtools/rust/rust-source.inc
@@ -6,6 +6,7 @@ SRC_URI += "https://static.rust-lang.org/dist/rustc-${RUST_VERSION}-src.tar.xz;n
             file://repro-issue-fix-with-cc-crate-hashmap.patch;patchdir=${RUSTSRC} \
             file://0001-src-core-build_steps-tool.rs-switch-off-lto-for-rust.patch;patchdir=${RUSTSRC} \
             file://0002-Fix-rust-build-failure-with-unstable-options.patch;patchdir=${RUSTSRC} \
+            file://0003-rustc-span-add-oe-knob-to-elide-cfg-version-from-stable-crate-id.patch;patchdir=${RUSTSRC} \
 "
 SRC_URI[rust.sha256sum] = "0ed06fdaffd4722a7702e0b4eebfafc897ab8f513e8e1b247cdd7e5c6df6ded2"
 
-- 
2.43.0

Re: [OE-core] [PATCH v2] rust: Avoid passing host-specific information to crates Strict Version Hash

[Mathieu Dubois-Briand]

On Tue Aug 25, 2026 at 1:56 AM CEST, Alejandro Hernandez Samaniego via lists.openembedded.org wrote:
> rustc computes each crate's Strict Version Hash (SVH) using inputs that include
> the *stage0/stage1 bootstrap compiler* fingerprint, which in turn depends on the
> build host arch.
>
> This eventually may cause sstate matches across architectures for artifacts that
> are actually different, causing autobuilder intermitent reproducibility issues.
>
> To avoid this, pass a fixed value instead of host-specific bits to the specified
> hash.
>
> [YOCTO #15554]
>
> Assisted-by: AI - OpenAI
> Signed-off-by: Alejandro Hernandez <alhe@linux.microsoft.com>

Hi Alejandro,

This looks broken here:

ERROR: rust-native-1.97.1-r0 do_install: Execution of '/srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work/x86_64-linux/rust-native/1.97.1/temp/run.do_install.2682640' failed with exit code 1
...
ERROR: Logfile of failure stored in: /srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work/x86_64-linux/rust-native/1.97.1/temp/log.do_install.2682640
...
|     Building [==================>      ] 275/348: object, schemars, tracing-s…
|    Compiling rustc_span v0.0.0 (/srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work-shared/rust-source-1.97.1-r0/sources/rustc-1.97.1-src/compiler/rustc_span)
|     Building [==================>      ] 276/348: object, schemars, tracing-s…
| error: expected `;`, found `StableCrateId`
|    --> /rustc-dev/8bab26f4f68e0e26f0bb7960be334d5b520ea452/compiler/rustc_span/src/def_id.rs:200:59
|     |
| 200 |         hasher.write(b"

https://autobuilder.yoctoproject.org/valkyrie/#/builders/4/builds/4510

Can you have a look at the issue?

Thanks,
Mathieu

-- 
Mathieu Dubois-Briand, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [OE-core] [PATCH v2] rust: Avoid passing host-specific information to crates Strict Version Hash

[Alejandro Hernandez]

On 8/25/2026 12:48 PM, Mathieu Dubois-Briand via lists.openembedded.org 
wrote:
> On Tue Aug 25, 2026 at 1:56 AM CEST, Alejandro Hernandez Samaniego via lists.openembedded.org wrote:
>> rustc computes each crate's Strict Version Hash (SVH) using inputs that include
>> the *stage0/stage1 bootstrap compiler* fingerprint, which in turn depends on the
>> build host arch.
>>
>> This eventually may cause sstate matches across architectures for artifacts that
>> are actually different, causing autobuilder intermitent reproducibility issues.
>>
>> To avoid this, pass a fixed value instead of host-specific bits to the specified
>> hash.
>>
>> [YOCTO #15554]
>>
>> Assisted-by: AI - OpenAI
>> Signed-off-by: Alejandro Hernandez <alhe@linux.microsoft.com>
> Hi Alejandro,
>
> This looks broken here:
>
> ERROR: rust-native-1.97.1-r0 do_install: Execution of '/srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work/x86_64-linux/rust-native/1.97.1/temp/run.do_install.2682640' failed with exit code 1
> ...
> ERROR: Logfile of failure stored in: /srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work/x86_64-linux/rust-native/1.97.1/temp/log.do_install.2682640
> ...
> |     Building [==================>      ] 275/348: object, schemars, tracing-s…
> |    Compiling rustc_span v0.0.0 (/srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work-shared/rust-source-1.97.1-r0/sources/rustc-1.97.1-src/compiler/rustc_span)
> |     Building [==================>      ] 276/348: object, schemars, tracing-s…
> | error: expected `;`, found `StableCrateId`
> |    --> /rustc-dev/8bab26f4f68e0e26f0bb7960be334d5b520ea452/compiler/rustc_span/src/def_id.rs:200:59
> |     |
> | 200 |         hasher.write(b"
>
> https://autobuilder.yoctoproject.org/valkyrie/#/builders/4/builds/4510
>
> Can you have a look at the issue?

I'll take a look



> Thanks,
> Mathieu
>
>
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Re: [OE-core] [PATCH v2] rust: Avoid passing host-specific information to crates Strict Version Hash

[Alejandro Hernandez]

On 8/25/2026 2:13 PM, Alejandro Hernandez Samaniego via 
lists.openembedded.org wrote:
>
> On 8/25/2026 12:48 PM, Mathieu Dubois-Briand via 
> lists.openembedded.org wrote:
>> On Tue Aug 25, 2026 at 1:56 AM CEST, Alejandro Hernandez Samaniego 
>> via lists.openembedded.org wrote:
>>> rustc computes each crate's Strict Version Hash (SVH) using inputs 
>>> that include
>>> the *stage0/stage1 bootstrap compiler* fingerprint, which in turn 
>>> depends on the
>>> build host arch.
>>>
>>> This eventually may cause sstate matches across architectures for 
>>> artifacts that
>>> are actually different, causing autobuilder intermitent 
>>> reproducibility issues.
>>>
>>> To avoid this, pass a fixed value instead of host-specific bits to 
>>> the specified
>>> hash.
>>>
>>> [YOCTO #15554]
>>>
>>> Assisted-by: AI - OpenAI
>>> Signed-off-by: Alejandro Hernandez <alhe@linux.microsoft.com>
>> Hi Alejandro,
>>
>> This looks broken here:
>>
>> ERROR: rust-native-1.97.1-r0 do_install: Execution of 
>> '/srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work/x86_64-linux/rust-native/1.97.1/temp/run.do_install.2682640' 
>> failed with exit code 1
>> ...
>> ERROR: Logfile of failure stored in: 
>> /srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work/x86_64-linux/rust-native/1.97.1/temp/log.do_install.2682640
>> ...
>> |     Building [==================>      ] 275/348: object, schemars, 
>> tracing-s…
>> |    Compiling rustc_span v0.0.0 
>> (/srv/pokybuild/yocto-worker/genericx86-64/build/build/tmp/work-shared/rust-source-1.97.1-r0/sources/rustc-1.97.1-src/compiler/rustc_span)
>> |     Building [==================>      ] 276/348: object, schemars, 
>> tracing-s…
>> | error: expected `;`, found `StableCrateId`
>> |    --> 
>> /rustc-dev/8bab26f4f68e0e26f0bb7960be334d5b520ea452/compiler/rustc_span/src/def_id.rs:200:59
>> |     |
>> | 200 |         hasher.write(b"
>>
>> https://autobuilder.yoctoproject.org/valkyrie/#/builders/4/builds/4510
>>
>> Can you have a look at the issue?
>
> I'll take a look
>
Looks like I made some mistakes when I rebased the patch onto the latest 
rust update that was just merged, sending v3



>
>
>> Thanks,
>> Mathieu
>>
>>
>>
>>
>
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