“What used to take endless minutes now takes a few seconds.”
Debian’s perf spawns a fresh addr2line process for every address it resolves. Thousands of them. The proper fix is linking libbfd, which Debian can’t ship because perf is GPLv2 only and libbfd is GPLv3+. So a license mismatch costs every Debian user minutes per profile. The patch keeps one addr2line running and talks to it over a pipe.