Add support for official libc formatting

[dstaley]

This PR updates the ldd content checks for family and version to account for distributions that are more closely aligned with the official formatting of ldd, which does not contain the string "GLIBC".

This allows faster checks on distros like Amazon Linux, openSUSE, Fedora, RHEL, Arch, and more without falling back to process.report.getReport().

[lovell]

Thank you for the PR Dylan.

Could checking for "libc" on its own, which feels rather generic, potentially lead to false positives? What does Bionic libc report? What if musl starts using the string "MUSL libc"?

Would a check for the explicit string "GNU libc" or similar be more robust?

[dstaley]

Great question! I definitely see how being a tad bit more generic could potentially lead to false positives (although I think, at present, those situations are theoretical rather than actually possible given the current file content of ldd for musl and bionic).

GNU libc isn't present, but GNU C Library or even This file is part of the GNU C Library could work, with the latter being highly unlikely to appear in any implementation that isn't at least derived from libc.

[lovell]

Thanks, if searching for "GNU C Library" improves things then that seems like a good option here.

$ docker run --rm -it amazonlinux:2 grep GNU /usr/bin/ldd
# This file is part of the GNU C Library.
# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# The GNU C Library is distributed in the hope that it will be useful,
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
    echo 'ldd (GNU libc) 2.26'

[lovell]

Thank you for the updates, I've left one comment inline about the failing musl-based Void test. (The failing glibc-based Void test is now fixed on the main branch so a rebase will get this passing.)

[lovell]

Thank you very much Dylan.

[lovell]

This change was included in v2.0.3.