libudev: add a non-system recipe

[valgur]

Summary

Changes to recipe: libudev/255.15

Motivation

libudev/system is used in several recipes on CCI, but like other system packages, it is not usable in a cross-compilation context.

• Resolves libudev libs: Host dependency and cross compilation #26161

Details

The libudev library is a part of systemd, but neither libsystemd or libudev depend on each other. I considered making it a component of libsystemd, but keeping them independent of each other seemed preferable, since they are not really used simultaneously in any recipes and it allows for a lighter libudev dependency. The only downside is slight duplication in the recipe.

The recipe cross-compiles successfully with aarch64-linux-gnu-gcc-14.

---

• Read the contributing guidelines
• Checked that this PR is not a duplicate: list of PRs by recipe
• Tested locally with at least one configuration using a recent version of Conan

[vithalsm]

@valgur (in continuation of other thread on cross compiling libudev from x86_64 to x86_64).
We tried with applying the diffs from this PR. However, libudev build is failing as it can't find a file 'sys/capability.h'. However, libcap is cross built and available for host.
I don't see INC path getting included (explicity), wondering whether that could be the issue.

If you can help us with quick look please. May be by cross building for x86.
============================ Build logs (error part) ===============
Command line: /usr/x86-10.3-glibc-2.34/bin/x86_64-myplat_buildroot-linux-gnu-gcc /home/aos-dev/.conan2/p/b/libud3200b2f38cb14/b/build-relwithdebinfo/meson-private/tmp3ule2c14/testfile.c -o /home/aos-dev/.conan2/p/b/libud3200b2f38cb14/b/build-relwithdebinfo/meson-private/tmp3ule2c14/output.obj -c --sysroot=/usr/myplat-sysroot -D_FILE_OFFSET_BITS=64 -O0 -std=gnu11 -> 0
Message: gperf len type is size_t
Running compile:
Working directory: /home/aos-dev/.conan2/p/b/libud3200b2f38cb14/b/build-relwithdebinfo/meson-private/tmp8pheyca2
Code:

    #ifdef __has_include
     #if !__has_include("sys/capability.h")
      #error "Header 'sys/capability.h' could not be found"
     #endif
    #else
     #include <sys/capability.h>
    #endif

---

Command line: /usr/x86-10.3-glibc-2.34/bin/x86_64-myplat_buildroot-linux-gnu-gcc /home/aos-dev/.conan2/p/b/libud3200b2f38cb14/b/build-relwithdebinfo/meson-private/tmp8pheyca2/testfile.c -E -P --sysroot=/usr/myplat-sysroot -D_FILE_OFFSET_BITS=64 -P -O0 -std=gnu11 -> 1
stderr:
/home/aos-dev/.conan2/p/b/libud3200b2f38cb14/b/build-relwithdebinfo/meson-private/tmp8pheyca2/testfile.c:4:12: error: #error "Header 'sys/capability.h' could not be found"
4 | #error "Header 'sys/capability.h' could not be found"
| ^~~~~

Has header "sys/capability.h" : NO

../src/meson.build:729:8: ERROR: Problem encountered: POSIX caps headers not found

[valgur]

@vithalsm Should be fixed now. Give it another try.

[vithalsm]

@vithalsm Should be fixed now. Give it another try.

@valgur Yes, its fixed and could build libudev successfully. Thanks again.
But, now, dpdk is failing as it can't find '-ludev'. Again, I don't see INC and LIB paths present in the command line. Something similar to libudev not finding libcap. Did you also observe and/or fixed same?

[vithalsm]

@vithalsm Should be fixed now. Give it another try.

@valgur Yes, its fixed and could build libudev successfully. Thanks again. But, now, dpdk is failing as it can't find '-ludev'. Again, I don't see INC and LIB paths present in the command line. Something similar to libudev not finding libcap. Did you also observe and/or fixed same?

Finally, could build 'dpdk' with additional changes as below -

1. Add 'libudev/255.15' in dependency list of dpdk recipe (require method)
2. Then, libudev version conflicted between /system (from rdma-core) and 255.15. Have to build dpdk with option ':with_libibverbs=False'.
   Then build went fine.
   Hope above info helps you in someway for your dpdk recipe.

[valgur]

@vithalsm i think the with_libibverbs=False itself might have been what fixed it for you, somehow. libcap is only used in dpdk libraries that link against libmlx4 and libmlx5 from rdma-core.

If you want to keep using dpdk with rdma-core, I suggest adding

[replace_requires]
libudev/system: libudev/255.15

to your profile to override the version everywhere.

[vithalsm]

@vithalsm i think the with_libibverbs=False itself might have been what fixed it for you, somehow. libcap is only used in dpdk libraries that link against libmlx4 and libmlx5 from rdma-core.

If you want to keep using dpdk with rdma-core, I suggest adding

[replace_requires]
libudev/system: libudev/255.15

to your profile to override the version everywhere.

@valgur thank you for this suggestion, was looking for exactly like this. It helped.