This is https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124828.

On Fri, Apr 10, 2026 at 1:15 AM ci_notify@linaro.org wrote:

Dear contributor,

Our automatic CI has detected problems related to your patch(es). Please find some details below.

In aarch64 native, after: | commit gcc-16-8510-g395e5cef29d9 | Author: Tomasz Kamiński tkaminsk@redhat.com | Date: Wed Apr 1 14:32:21 2026 +0200 | | libstdc++: Export explicit instantiations for C++20 members of std::string | | The C++20 standard added new starts_with and ends_with members to | std::basic_string, which were not previously instantiated in the library. | This meant that the extern template declarations had to be disabled for | ... 31 lines of the commit log omitted.

Produces 1 regression: | | regressions.sum: | Running g++:g++.dg/lto/lto.exp ... | FAIL: g++.dg/lto/20091022-2 cp_lto_20091022-2_0.o-cp_lto_20091022-2_0.o link, -O3 -flto -Winline

Used configuration : *CI config* tcwg_gcc_check aarch64-linux-gnu *configure and test flags:* none, autodetected on aarch64-unknown-linux-gnu--disable-multilib --enable-fix-cortex-a53-835769 --enable-fix-cortex-a53-843419 --with-arch=armv8-a

We track this bug report under https://linaro.atlassian.net/browse/GNU-1869. Please let us know if you have a fix.

If you have any questions regarding this report, please ask on linaro-toolchain@lists.linaro.org mailing list.

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The information below contains the details of the failures, and the ways to reproduce a debug environment:

You can find the failure logs in *.log.1.xz files in

http://54.172.246.49:9090/jobs/tcwg_gcc_check--master-aarch64-build/builds/1... The full lists of regressions and improvements as well as configure and make commands are in

http://54.172.246.49:9090/jobs/tcwg_gcc_check--master-aarch64-build/builds/1... The list of [ignored] baseline and flaky failures are in

http://54.172.246.49:9090/jobs/tcwg_gcc_check--master-aarch64-build/builds/1...

Current build : http://54.172.246.49:9090/jobs/tcwg_gcc_check--master-aarch64-build/builds/1... Reference build : http://54.172.246.49:9090/jobs/tcwg_gcc_check--master-aarch64-build/builds/1...

Instruction to reproduce the build : https://gitlab.com/LinaroLtd/tcwg/ci/interesting-commits/-/raw/master/gcc/sh...

Full commit : See in git+ssh://linaroci@gcc.gnu.org/git/gcc.git