[RFC][PATCH 1/1][bionic] UBUNTU: [Packaging] do not use ${shlibs:Depends} for image or modules

[Thadeu Lima de Souza Cascardo]

On Tue, Jul 10, 2018 at 12:17:39PM -0700, Kamal Mostafa wrote:
> Resolve build warnings for the main image and modules packages which
> have no shared lib dependencies and hence get no generated
> ${shlibs:Depends} variable, resulting in:
> 
>     dpkg-gencontrol: warning: Depends field of package PACKAGE:
>         unknown substitution variable ${shlibs:Depends}
> 
> for PACKAGE's:
> 
>     linux-image-unsigned-4.15.0-24-generic
>     linux-image-unsigned-4.15.0-24-lowlatency
>     linux-modules-4.15.0-24-generic
>     linux-modules-4.15.0-24-lowlatency
>     linux-modules-extra-4.15.0-24-generic
> 
> Signed-off-by: Kamal Mostafa <kamal at canonical.com>
> ---

We use dh_shlibdeps instead of calling dpkg-shlibdeps directly. That means it's
looking for the installed ELF files. Up to compat 10, it was either looking for
executable files or matching names (.so and a few others). After compat 11, it
looks for ELF headers, but that won't match the modules, as they are not
dynamic ELF executables or ELF shared objects (it matches only those ELF
types).

On the other hand, we still call dh_shlibdeps for those packages that don't
need it. So, I would complement this change with removing those calls.

In the investigation, it was interesting finding out that the headers package
contains some executables from the scripts directory, some of which are dynamic
linked, causing the package to depend on those. So, we need to take care do
keep shlibs for that, not only the other userspace tools.

Cascardo.

>  debian.master/control.d/flavour-control.stub | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/debian.master/control.d/flavour-control.stub b/debian.master/control.d/flavour-control.stub
> index 918b41a..2cc4711 100644
> --- a/debian.master/control.d/flavour-control.stub
> +++ b/debian.master/control.d/flavour-control.stub
> @@ -27,7 +27,7 @@ Architecture: ARCH
>  Section: kernel
>  Priority: optional
>  Provides: linux-image, fuse-module, aufs-dkms, =PROVIDES=${linux:rprovides}
> -Depends: ${misc:Depends}, ${shlibs:Depends}, kmod, linux-base (>= 4.5ubuntu1~16.04.1), linux-modules-PKGVER-ABINUM-FLAVOUR
> +Depends: ${misc:Depends}, kmod, linux-base (>= 4.5ubuntu1~16.04.1), linux-modules-PKGVER-ABINUM-FLAVOUR
>  Recommends: BOOTLOADER, initramfs-tools | linux-initramfs-tool
>  Breaks: flash-kernel (<< 3.90ubuntu2) [arm64 armhf], s390-tools (<< 2.3.0-0ubuntu3) [s390x]
>  Conflicts: linux-image=SIGN-PEER-PKG=-PKGVER-ABINUM-FLAVOUR
> @@ -49,7 +49,7 @@ Build-Profiles: <!stage1>
>  Architecture: ARCH
>  Section: kernel
>  Priority: optional
> -Depends: ${misc:Depends}, ${shlibs:Depends}
> +Depends: ${misc:Depends}
>  Description: Linux kernel extra modules for version PKGVER on DESC
>   Contains the corresponding System.map file, the modules built by the
>   packager, and scripts that try to ensure that the system is not left in an
> @@ -68,7 +68,7 @@ Build-Profiles: <!stage1>
>  Architecture: ARCH
>  Section: kernel
>  Priority: optional
> -Depends: ${misc:Depends}, ${shlibs:Depends}, linux-image-PKGVER-ABINUM-FLAVOUR | linux-image-unsigned-PKGVER-ABINUM-FLAVOUR, crda | wireless-crda
> +Depends: ${misc:Depends}, linux-image-PKGVER-ABINUM-FLAVOUR | linux-image-unsigned-PKGVER-ABINUM-FLAVOUR, crda | wireless-crda
>  Description: Linux kernel extra modules for version PKGVER on DESC
>   This package contains the Linux kernel extra modules for version PKGVER on
>   DESC.
> -- 
> 2.7.4
> 
> 
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