It seems that upstream added a few tests at some point. Need to investigate whether they work with standalone builds, and how to run them.
Looks like tests require some parts of libcxx to work. Need to investigate further.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=ee6810253547c6ec221b37ff8ffde0b8a0c27d2b commit ee6810253547c6ec221b37ff8ffde0b8a0c27d2b Author: Michał Górny <mgorny@gentoo.org> AuthorDate: 2018-01-19 20:26:59 +0000 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: 2018-01-20 08:54:38 +0000 sys-libs/llvm-libunwind: Enable testing Closes: https://bugs.gentoo.org/645044 .../llvm-libunwind/llvm-libunwind-6.0.9999.ebuild | 42 +++++++++++++++++++-- sys-libs/llvm-libunwind/llvm-libunwind-9999.ebuild | 44 ++++++++++++++++++++-- 2 files changed, 79 insertions(+), 7 deletions(-)