This is an auto-filed bug because sys-block/spindown calls g++ 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 CXX implementation (like clang++) by setting the CXX variable. So this issue has been reproduced by setting the CXX variable to x86_64-pc-linux-gnu-g++ and by removing the /usr/bin/g++ - /usr/bin/c++ binaries.
Created attachment 642204 [details]
build log and emerge --info
The bug has been closed via the following commit(s):
Author: Sam James <email@example.com>
AuthorDate: 2023-01-23 02:20:59 +0000
Commit: Sam James <firstname.lastname@example.org>
CommitDate: 2023-01-23 02:32:54 +0000
sys-block/spindown: EAPI 8, respect CXX, fix musl build
Signed-off-by: Sam James <email@example.com>
.../spindown/files/spindown-0.4.0-Makefile.patch | 55 ++++++++++++++++++++++
.../files/spindown-0.4.0-musl-time-include.patch | 11 +++++
sys-block/spindown/spindown-0.4.0-r5.ebuild | 26 +++++-----
3 files changed, 80 insertions(+), 12 deletions(-)