Update from 7.3.0-15 to 7.3.0-16 based GCC causes lintian problems

[Mario Limonciello]

Upstream fwupd runs CI with Debian testing and Ubuntu devel. As part of that CI we run lintian after a packaged build.
A few days ago we started noticing failures in Ubuntu first and then Debian later (probably because Ubuntu pulled in the -16 based GCC-7 before it migrated to Debian testing):

E: fwupd: library-not-linked-against-libc usr/lib/x86_64-linux-gnu/fwupd-plugins-3/libfu_plugin_upower.so
E: fwupd-tests: library-not-linked-against-libc usr/lib/x86_64-linux-gnu/fwupd-plugins-3/libfu_plugin_test.so

I examined the files and sure enough they don't have libc.s.6 marked NEEDED.

Compiling with the older compiler (or clang) they do.

Newer:
$ objdump -x build/obj-x86_64-linux-gnu/plugins/test/libfu_plugin_test.so | grep needed -i
  NEEDED libgobject-2.0.so.0
  NEEDED libglib-2.0.so.0

Older:
$ objdump -x build/obj-x86_64-linux-gnu/plugins/test/libfu_plugin_test.so | grep needed -i
  NEEDED libgobject-2.0.so.0
  NEEDED libglib-2.0.so.0
  NEEDED libpthread.so.0
  NEEDED libc.so.6

We were looking at this upstream and find that it only happens if the compiler optimization is set to -O2. (which is our default). Setting it to -O0 the problem goes away.

[Mario Limonciello (superm1)]

Per discussion in the Debian bug, this is actually a lintian bug.

fwupd has chosen to ignore this error.
https://github.com/hughsie/fwupd/commit/8600b644dffe8339b39564e601f5dde2517b5802

[lamby (lamby)]

> Per discussion in the Debian bug, this is actually a lintian bug.

What's the Debian bug#?

[Mario Limonciello (superm1)]

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=896012