[PATCH v3 1/4] configure.ac, src/: add C++20, add new stackprof tool

[Serhei Makarov]

On Fri, Jul 24, 2026, at 3:40 PM, Serhei Makarov wrote:
> eu-stackprof is a new tool which profiles processes on a Linux system
> using perf_events and outputs gprof gmon.out format program counter
> histograms and callgraph-arc profiles; intended as an updated demo of
> libdwfl_stacktrace functionality and as a data-gathering tool for the
> profiledb initiative.
Worth re-flagging for advice: this currently fails one of the trybots (fedora-x86_64) at 'make rpmbuild' due to libpfm-devel:
https://builder.sourceware.org/buildbot/#/builders/209/builds/328/steps/9/logs/stdio

I'm not sure if the specfile needs to be adjusted (surely not, we have added "BuildRequires: libpfm-devel" which should be fine in a fedora context) or if the particular buildbot just needs libpfm-devel installed, or what. The other buildbots seem fine, including 'make check'.