First Impish Indri test rebuild / GCC 11

[Matthias Klose]

The first test rebuild of Impish Indri was started on August 05 2021 for
all architectures, all components. The rebuild is finished on amd64 and i386 for
all components, and finished for all architectures for the main component.
Still running for universe and multiverse for non-x86 architectures.

Results (please also look at the superseded builds) can be found at

https://people.canonical.com/~doko/ftbfs-report/test-rebuild-20210805-impish-impish.html

The rebuild was done with a few packages which are not yet in the impish release
pocket.  These are:

 - glibc 2.34
 - linux (linux-libc-dev), only in the proposed pocket
 - golang-defaults pointing to golang-1.17

GCC 11 is now the default compiler; there are no bug reports filed in LP for
build failures triggered by GCC 11, however there are reports in the Debian BTS.
http://bugs.debian.org/cgi-bin/pkgreport.cgi?tag=ftbfs-gcc-11;users=debian-gcc@lists.debian.org

Porting advice can be found at https://gcc.gnu.org/gcc-11/porting_to.html

The additional packages used for the test rebuild are found in the PPA
https://launchpad.net/~ubuntu-toolchain-r/+archive/ubuntu/volatile


Additional build failures for packages in hirsute-proposed (not yet in hirsute)
can be found at http://qa.ubuntuwire.com/ftbfs/

Please help fixing the build failures.

Matthias