Re: [PATCH 0/1] libevl: Add debian package config

Hi Hannes,

thanks for carrying this over.

On 17.07.26 22:58, Hannes Diethelm wrote:
> This patch adds a debian package config that allows to build a deb's
> using dpkg-buildpackage -b -uc.
> 
> The packages are libevl / libevl-test similar to[1]. However, latmus
> is placed in libevl. One might not need the tests but still want to
> use latmus.

For the purpose of tuning the core, or what is the reasoning here?

> 
> Additionally, libevl installs /usr/lib/udev/rules.d/90-libevl.rules which sets all evl
> device files to group evl, g+rw. libevl.postinst adds this group and triggers an udev reload.
> 
> This allows to use libevl without root. However, using SCHED_FIFO still
> needs either root or setcap cap_sys_nice+ep and possibly some other tweaks.
> Some tests and my application work with cap_sys_nice+ep. However, for example latmus fails
> due to unknown reasons. The debian packages sets no capabilities but this could be added
> if desired.
> 
> Caveats:
> 
> The test ptrace-sync fails with <timeout waiting for gdb>. dh_strip -Xptrace-sync from[1]
> does not help and it is not needed: When libevl-test-dbgsym is installed, the symbols are
> available but the test still fails. With dh_strip -Xptrace-sync, the symbols are not found:
> warning: could not find '.gnu_debugaltlink' file for /usr/libexec/evl/tests/ptrace-sync

But the package built by xenomai-images does not have this problem and
runs the ptrace test successfully. Already dug into the key differences?

> 
> If linux-evl is also built and installed as a debian package, linux-libc-dev can not be
> installed due to /usr/include/evl/*-abi.h are both installed by libevl and linux-libc-dev
> from the kernel build. However, installing linux-libc-dev from debian trixie works fine.

This looks wrong: The kernel is providing us with a different UAPI, thus
also needs to deliver an alternative linux-libc-dev package. It should
be the role of libevl to deliver those headers as it has no knowledge
about the actual kernel in use here. That's why xenomai-images is
generating a new linux-libc-dev and is not relying on libevl here.

Jan

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