Bug#1115395: dpkg-shlibdeps fails to find libraries if /lib is removed from ld.so.conf search path

Package: dpkg-dev
Version: 1.22.21
Severity: important
File: /usr/bin/dpkg-shlibdeps

Hi Guillem,

for some back story please see 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1111805#49

In https://salsa.debian.org/glibc-team/glibc/-/commit/5e3aa111654e9aad080881fb98f9e5b01b277857
(currently only available via Debian experimental),
the duplicated paths for /lib were removed from ld.so.conf files.

This triggered a build failure for ncl, hdf-eos5 and ruby-hdfeos5.

All those packages link against libgctp and the build failures look
similar:


hdf-eos5:

dpkg-shlibdeps: error: no dependency information found for /usr/lib/x86_64-linux-gnu/libgctp-2.0.0.so (used by debian/libhe5-hdfeos0t64/usr/lib/x86_64-linux-gnu/libhe5_hdfeos.so.0.0.0)
dpkg-shlibdeps: hint: check if the library actually comes from a package
dh_shlibdeps: error: dpkg-shlibdeps -Tdebian/libhe5-hdfeos0t64.substvars debian/libhe5-hdfeos0t64/usr/lib/x86_64-linux-gnu/libhe5_hdfeos.so.0.0.0 returned exit code 1

ncl:

dpkg-shlibdeps: error: no dependency information found for /usr/lib/x86_64-linux-gnu/libgctp-2.0.0.so (used by debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGncl.so.1)
dpkg-shlibdeps: hint: check if the library actually comes from a package
dh_shlibdeps: error: dpkg-shlibdeps -Tdebian/libncarg0t64.substvars debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGgksPS.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGmisc2.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGllu.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGras.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGcgm.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGff.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGgksPDF.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGgksX.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libfftpack5_dp.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGnfpfort.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGgksCTXT.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGlluC.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGmp.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGmisc.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGgks.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGhlu.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGncl.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGctrans.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGmath.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGc.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGnfp.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGcn.so.1 debian/libncarg0t64/usr/lib/x86_64-linux-gnu/libNGictrans.so.1 returned exit code 1
dh_shlibdeps: error: Aborting due to earlier error
make: *** [debian/rules:14: binary] Error 25


ruby-hdfeos5:

dpkg-shlibdeps: error: no dependency information found for /usr/lib/x86_64-linux-gnu/libgctp-2.0.0.so (used by debian/ruby-hdfeos5/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/3.3.0/numru/hdfeos5raw.so)
dpkg-shlibdeps: hint: check if the library actually comes from a package
dh_shlibdeps: error: dpkg-shlibdeps -Tdebian/ruby-hdfeos5.substvars debian/ruby-hdfeos5/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/3.3.0/numru/hdfeos5raw.so returned exit code 1
dh_shlibdeps: error: Aborting due to earlier error
make: *** [debian/rules:18: binary] Error 25



If you want to reproduce the problem, remove the line
/lib/x86_64-linux-gnu
in /etc/ld.so.conf.d/x86_64-linux-gnu.conf and try to build one of those
packages in debian sid or trixie.

It is unclear to me, if this is a problem in libgctp, dpkg-shlibdeps or
the affected packages themselves. I decided to file it against
dpkg(-shlibdeps) as it is the command failing.
I chose severity important (as it makes packages FTBFS) and it probably
should be bumped to RC once glibc with that change is uploaded to
unstable.

The setup of libgctp is a bit special as detailed in 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1111805#69

As Aurelien pointed out, while special it should still be covered
according to the dpkg-shlibdeps documentation but maybe it is hitting
less tested code paths.

Would very much appreciate your input on this matter.

Michael


-- System Information:
Debian Release: forky/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 6.16.7+deb14-amd64 (SMP w/16 CPU threads; PREEMPT)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages dpkg-dev depends on:
ii  binutils      2.45-7
ii  bzip2         1.0.8-6
ii  libdpkg-perl  1.22.21
ii  make          4.4.1-2
ii  patch         2.8-2
ii  perl          5.40.1-6
ii  tar           1.35+dfsg-3.1
ii  xz-utils      5.8.1-1.1

Versions of packages dpkg-dev recommends:
ii  build-essential          12.12
ii  fakeroot                 1.37.1.2-1
ii  gcc [c-compiler]         4:15.2.0-4
ii  gcc-15 [c-compiler]      15.2.0-4
ii  gnupg                    2.4.8-3
ii  gpgv                     2.4.8-3
ii  libalgorithm-merge-perl  0.08-5
ii  sqv                      1.3.0-3

Versions of packages dpkg-dev suggests:
ii  debian-keyring             2025.07.26
pn  debian-tag2upload-keyring  <none>

-- no debconf information