Re: [OE-core] [PATCH v7 01/14] linux-yocto: conditionally add clang/rust/bindgen-cli-native to DEPENDS

Bruce Ashfield
2026-03-09T18:01:39Z

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On Mon, Mar 9, 2026 at 12:54 PM Harish Sadineni <
Harish.Sadineni@windriver.com> wrote:

>
> On 3/9/2026 9:59 PM, Bruce Ashfield wrote:
>
> *CAUTION: This email comes from a non Wind River email account!*
> Do not click links or open attachments unless you recognize the sender and
> know the content is safe.
>
>
> On Mon, Mar 9, 2026 at 12:10 PM Harish Sadineni <
> Harish.Sadineni@windriver.com> wrote:
>
>>
>> On 3/9/2026 4:56 PM, Richard Purdie wrote:
>>
>> CAUTION: This email comes from a non Wind River email account!
>> Do not click links or open attachments unless you recognize the sender and know the content is safe.
>>
>> On Wed, 2026-03-04 at 09:43 -0800, Sadineni, Harish via lists.openembedded.org <https://urldefense.com/v3/__http://lists.openembedded.org__;!!AjveYdw8EvQ!cWPq0za66UhcuPm1JB9FSYJ5JMWWpL_480vZLcrK0BTZbuoPaFvjdJly1r2bF4S-jo8X5LrrrXkmL3xU90Zr5Er_U2VxaLk$> wrote:
>>
>> From: Harish Sadineni <Harish.Sadineni@windriver.com> <Harish.Sadineni@windriver.com>
>>
>> Conditionally add 'clang-native', 'rust-native' and 'bindgen-cli-native' to 'DEPENDS'
>> when Kernel Rust Support is enabled.
>>
>> These tools are required for building Rust-enabled kernels and for
>> generating Rust FFI bindings via bindgen during the kernel build.
>>
>> This ensures the additional dependencies are only pulled in when
>> Rust support is explicitly enabled, avoiding unnecessary native
>> dependencies for non-Rust kernel builds.
>>
>> Signed-off-by: Harish Sadineni <Harish.Sadineni@windriver.com> <Harish.Sadineni@windriver.com>
>> ---
>> meta/recipes-kernel/linux/linux-yocto.inc <https://urldefense.com/v3/__http://linux-yocto.inc__;!!AjveYdw8EvQ!cWPq0za66UhcuPm1JB9FSYJ5JMWWpL_480vZLcrK0BTZbuoPaFvjdJly1r2bF4S-jo8X5LrrrXkmL3xU90Zr5Er_ybuc9RA$> | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/meta/recipes-kernel/linux/linux-yocto.inc <https://urldefense.com/v3/__http://linux-yocto.inc__;!!AjveYdw8EvQ!cWPq0za66UhcuPm1JB9FSYJ5JMWWpL_480vZLcrK0BTZbuoPaFvjdJly1r2bF4S-jo8X5LrrrXkmL3xU90Zr5Er_ybuc9RA$> b/meta/recipes-kernel/linux/linux-yocto.inc <https://urldefense.com/v3/__http://linux-yocto.inc__;!!AjveYdw8EvQ!cWPq0za66UhcuPm1JB9FSYJ5JMWWpL_480vZLcrK0BTZbuoPaFvjdJly1r2bF4S-jo8X5LrrrXkmL3xU90Zr5Er_ybuc9RA$>
>> index 4d0a726bb6..b7961bbcdf 100644
>> --- a/meta/recipes-kernel/linux/linux-yocto.inc <https://urldefense.com/v3/__http://linux-yocto.inc__;!!AjveYdw8EvQ!cWPq0za66UhcuPm1JB9FSYJ5JMWWpL_480vZLcrK0BTZbuoPaFvjdJly1r2bF4S-jo8X5LrrrXkmL3xU90Zr5Er_ybuc9RA$>
>> +++ b/meta/recipes-kernel/linux/linux-yocto.inc <https://urldefense.com/v3/__http://linux-yocto.inc__;!!AjveYdw8EvQ!cWPq0za66UhcuPm1JB9FSYJ5JMWWpL_480vZLcrK0BTZbuoPaFvjdJly1r2bF4S-jo8X5LrrrXkmL3xU90Zr5Er_ybuc9RA$>
>> @@ -76,11 +76,14 @@ do_install:append(){
>> KERNEL_FEATURES:append:qemuall = " features/kernel-sample/kernel-sample.scc"
>>
>> KERNEL_DEBUG ?= ""
>> +KERNEL_RUST_SUPPORT ?= ""
>> # These used to be version specific, but are now common dependencies. New
>> # tools / dependencies will continue to be added in version specific recipes.
>> DEPENDS += '${@bb.utils.contains_any("ARCH", [ "x86", "arm64", "powerpc" ], "elfutils-native", "", d)}'
>> DEPENDS += "openssl-native util-linux-native"
>> DEPENDS += "gmp-native libmpc-native"
>> +RUST_KERNEL_DEPENDS ?= "${@bb.utils.contains('KERNEL_RUST_SUPPORT', 'True', 'clang-native rust-native bindgen-cli-native', '', d)}" <$%7B@bb.utils.contains('KERNEL_RUST_SUPPORT','True','clang-nativerust-nativebindgen-cli-native','',d)%7D>
>> +DEPENDS += "${RUST_KERNEL_DEPENDS}"
>>
>> # Some options depend on CONFIG_PAHOLE_VERSION, so need to make pahole-native available before do_kernel_configme
>> do_kernel_configme[depends] += '${@bb.utils.contains("KERNEL_DEBUG", "True", "pahole-native:do_populate_sysroot", "", d)}'
>>
>> I thought we were going to try and use KERNEL_FEATURES for this?
>>
>> Hi Richard,
>>
>> I have tried this but i got circular dependency error with
>> KERNEL_FEATURES. So, I opted using variable KERNEL_RUST_SUPPORT.
>>
>
> I'm curious about that. Can you share the details ? (diff and the bitbake
> error)
>
>
> As discussed previously, I attempted to use the following in
> meta/recipes-kernel/linux/linux-yocto_6.18.bb:
>
> KERNEL_FEATURES:append = " ${@bb.utils.contains('KERNEL_FEATURES',
> 'rust-kernel', ' features/kernel-rust/kernel-rust.scc', '', d)}"
>
> This resulted in a BitBake variable dependency chain failure. The issue
> occurs because the expression is trying to read KERNEL_FEATURES
> while simultaneously modifying KERNEL_FEATURES, which creates a circular
> dependency.
>

Yes, that's clearly not going to work, but that wouldn't have been the
suggestion.

Wasn't Richard asking about setting the RUST_KERNEL_DEPENDS based on the
KERNEL_FEATURES containing rust.scc ?

Bruce

>
> example:
> The variable dependency chain for the failure is: KERNEL_FEATURES ->
> KERNEL_FEATURES -> KERNEL_FEATURES -> KERNEL_FEATURES...
>
> Thanks,
> Harish
>
>
> Bruce
>
>
>
>> The implementation of KERNEL_RUST_SUPPORT is problematic as it only
>> works for the value of "True", not "true", or "1" or 1 or any other
>> thing people might dream up. "Contains" isn't really an appropriate
>> mechanism for a boolean either.
>>
>> You can use bb.utils.to_boolean() as a way to better obtain a boolean
>> value from a random variable.
>>
>> Understood, Earlier i took reference from the code that already present
>> in that file.
>> I have updated the code we will send v8.
>>
>> Thanks,
>> Harish
>>
>> Cheers,
>>
>> Richard
>>
>>
>>
>>
>>
>>
>>
>
> --
> - Thou shalt not follow the NULL pointer, for chaos and madness await thee
> at its end
> - "Use the force Harry" - Gandalf, Star Trek II
>
>

--
- Thou shalt not follow the NULL pointer, for chaos and madness await thee
at its end
- "Use the force Harry" - Gandalf, Star Trek II

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