This is an auto-filed bug because sci-astronomy/missfits calls ar directly.
The issue was originally discovered on amd64, but it may be reproducible on other arches as well.
If you think that a different summary clarifies the issue better, feel free to change it.
Attached build log and emerge --info.
If you think it doesn't make sense fix these type of issues, I'd like to point out that won't be possible use a different AR implementation (like llvm-ar) by setting the AR variable. So this issue has been reproduced by setting the AR variable to x86_64-pc-linux-gnu-ar and by removing the /usr/bin/ar binary.
Created attachment 641702 [details]
build log and emerge --info
The bug has been closed via the following commit(s):
Author: David Seifert <email@example.com>
AuthorDate: 2020-10-04 13:21:22 +0000
Commit: David Seifert <firstname.lastname@example.org>
CommitDate: 2020-10-04 13:21:22 +0000
sci-astronomy/missfits: Fix -fno-common
Package-Manager: Portage-3.0.8, Repoman-3.0.1
Signed-off-by: David Seifert <email@example.com>
.../missfits/files/missfits-2.8.0-fno-common.patch | 65 ++++++++++++++++++++++
.../files/missfits-2.8.0-run-AM_PROG_AR.patch | 10 ++++
sci-astronomy/missfits/missfits-2.8.0.ebuild | 20 +++++--
3 files changed, 89 insertions(+), 6 deletions(-)