Bug#939871: glibc: python3:native build dependency incorrectly marked as <!nocheck>

[Sven Joachim <svenjoac@gmx.de>]

Source: glibc
Version: 2.29-1
Severity: normal

According to the INSTALL file, Python is now required to build glibc:

,----
|    * Python 3.4 or later
|
|      Python is required to build the GNU C Library.  As of release time,
|      Python 3.7.1 is the newest verified to work for building and
|      testing the GNU C Library.
`----

Indeed, building with the nocheck profile in a python-less chroot fails:

,----
| $ sbuild --no-arch-all --arch=i386 --profiles=nocheck
| [...]
| checking if i686-linux-gnu-gcc-9 is sufficient to build libc... yes
| checking for i686-linux-gnu-nm... i686-linux-gnu-nm
| checking for python3... no
| checking for python... no
| configure: error:
| *** These critical programs are missing or too old: python
| *** Check the INSTALL file for required versions.
| make: *** [debian/rules.d/build.mk:66: /<<PKGBUILDDIR>>/stamp-dir/configure_libc] Error 1
| dpkg-buildpackage: error: debian/rules build-arch subprocess returned exit status 2
`----


-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (101, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.3.0-rc8-nouveau (SMP w/2 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)