This is an auto-filed bug because sys-cluster/singularity calls cc 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 CC implementation (like clang) by setting the CC variable. So this issue has been reproduced by setting the CC variable to x86_64-pc-linux-gnu-gcc and by removing the /usr/bin/cc - /usr/bin/gcc binaries.
Created attachment 642192 [details]
build log and emerge --info
The bug has been closed via the following commit(s):
Author: Marek Szuba <email@example.com>
AuthorDate: 2020-09-01 14:01:51 +0000
Commit: Marek Szuba <firstname.lastname@example.org>
CommitDate: 2020-09-01 14:01:51 +0000
sys-cluster/singularity: honour toolchain values of CC and CXX
Signed-off-by: Marek Szuba <email@example.com>
sys-cluster/singularity/singularity-3.6.1.ebuild | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)