[Buildroot] [PATCH] package/python-grpcio: disable for the MIPS n32 ABI

[Buildroot] [PATCH] package/python-grpcio: disable for the MIPS n32 ABI

[Yegor Yefremov via buildroot]

From: Yegor Yefremov <yegorslists@googlemail.com>

The bundled abseil-cpp only implements DirectMmap() with mmap2 for the
o32 ABI on MIPS:

    #if ... (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32) || ...

With the n32 ABI, the "remaining 64-bit architectures" fallback is
selected instead, which fails to build because long is 32-bit there:

    third_party/abseil-cpp/absl/base/internal/direct_mmap.h:130:39:
        error: static assertion failed: Platform is not 64-bit
      130 |   static_assert(sizeof(unsigned long) == 8, "Platform is not 64-bit");
          |                 ~~~~~~~~~~~~~~~~~~~~~~^~~~
    third_party/abseil-cpp/absl/base/internal/direct_mmap.h:130:39:
        note: the comparison reduces to '(4 == 8)'

Upstream abseil has no support for the n32 ABI, so disable the package
for that ABI. The o32 and n64 ABIs are unaffected.

Assisted-by: Claude:claude-opus-5
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
---
 package/python-grpcio/Config.in | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/package/python-grpcio/Config.in b/package/python-grpcio/Config.in
index 6119991c7e..f52e19dc18 100644
--- a/package/python-grpcio/Config.in
+++ b/package/python-grpcio/Config.in
@@ -6,6 +6,11 @@ config BR2_PACKAGE_PYTHON_GRPCIO_ARCH_SUPPORTS
 	default y if BR2_i386 || BR2_x86_64
 	default y if BR2_mips || BR2_mipsel || BR2_mips64 || BR2_mips64el
 	default y if BR2_riscv
+	# The bundled abseil-cpp only implements DirectMmap() for the o32
+	# ABI on MIPS, and its 64-bit fallback fails to build with the n32
+	# ABI, where long is 32-bit. See
+	# third_party/abseil-cpp/absl/base/internal/direct_mmap.h
+	depends on !BR2_MIPS_NABI32
 
 config BR2_PACKAGE_PYTHON_GRPCIO
 	bool "python-grpcio"
-- 
2.34.1

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Re: [Buildroot] [PATCH] package/python-grpcio: disable for the MIPS n32 ABI

[Thomas Petazzoni via buildroot]

Hello,

Thanks a lot for this patch. Number of questions below.

On Tue, Sep 08, 2026 at 11:35:38AM +0200, Yegor Yefremov via buildroot wrote:
> From: Yegor Yefremov <yegorslists@googlemail.com>
> 
> The bundled abseil-cpp only implements DirectMmap() with mmap2 for the
> o32 ABI on MIPS:
> 
>     #if ... (defined(__mips__) && _MIPS_SIM == _MIPS_SIM_ABI32) || ...
> 
> With the n32 ABI, the "remaining 64-bit architectures" fallback is
> selected instead, which fails to build because long is 32-bit there:
> 
>     third_party/abseil-cpp/absl/base/internal/direct_mmap.h:130:39:
>         error: static assertion failed: Platform is not 64-bit
>       130 |   static_assert(sizeof(unsigned long) == 8, "Platform is not 64-bit");
>           |                 ~~~~~~~~~~~~~~~~~~~~~~^~~~
>     third_party/abseil-cpp/absl/base/internal/direct_mmap.h:130:39:
>         note: the comparison reduces to '(4 == 8)'

So assume this is fixing:

  https://autobuild.buildroot.net/results/90405c0a3d0b2e929d5074305906e6fe3679298c/

 ?

If so, can you add a Fixes: tag?

Also, can you investigate since when this problem exists, so that our
LTS maintainers can understand whether they need to backport this fix
or not?

> Upstream abseil has no support for the n32 ABI, so disable the package
> for that ABI. The o32 and n64 ABIs are unaffected.

But then doesn't package/abseil-cpp/Config.in also need to be
modified?

And is it possible for python-grpcio to use the Buildroot-provided
abseil, instead of using its bundled version?

Thanks a lot!

Thomas
-- 
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering and training
https://bootlin.com
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