media-sound/easyeffects will fail with "You need at least GCC 8 or Clang 10 for C++20-specific compiler flags" when using gcc 9. From the gcc website: C++20 features are available since GCC 8. To enable C++20 support, add the command-line parameter -std=c++20 (use -std=c++2a in GCC 9 and earlier) to your g++ command line. Or, to enable GNU extensions in addition to C++20 features, add -std=gnu++20. test-flag-CXX from the ebuild uses -std=c++20 that will fail on gcc 9 and earler.
Continuing along, turns out easyeffects will not compile with gcc 9 due to missing "#include <ranges>" headers. Info from https://stackoverflow.com/questions/56118941/do-we-have-c20-ranges-library-in-gcc-9
I think you're asking for us to update the message to say "at least GCC 10"?
(In reply to Sam James from comment #2) > I think you're asking for us to update the message to say "at least GCC 10"? oh, or try -std=c++2a first
I submitted it at first as an ebuild bug, but then after filing this bug report, discovered that it won't work on gcc 9 to begin with. So the fix is to update the error message from gcc 8 to gcc 10 or later is required. Only gcc 9 need the different flag for the test.
The bug has been closed via the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=3d14f524eb0d5369e57a0f13127bcd5341732a09 commit 3d14f524eb0d5369e57a0f13127bcd5341732a09 Author: Marek Szuba <marecki@gentoo.org> AuthorDate: 2022-01-01 14:01:04 +0000 Commit: Marek Szuba <marecki@gentoo.org> CommitDate: 2022-01-01 14:10:57 +0000 media-sound/easyeffects: update "no C++20 support" error message gcc versions older than 10 require -std value "c++2a" rather than "c++20". Since tests and research conducted by the user who reported this problem show that easyeffects-6 cannot be built using gcc-9 owing to the fact the <ranges> library has only been available in gcc since 10.1 (fortunately we do not have to handle the 10.0 case here because the oldest gcc-10 version currently in the tree is 10.3.0), along with the age of gcc-9, we shan't even bother even bother patching meson.build to support the old value. Closes: https://bugs.gentoo.org/830256 Signed-off-by: Marek Szuba <marecki@gentoo.org> media-sound/easyeffects/easyeffects-6.1.5.ebuild | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
