https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94454
--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> --- there's a gist here: https://gist.github.com/jwakely/e131d3a268a78764458186eff02f29ec with Jonathan's valgrind session and some debug output from one case where I managed to catch the fail under a debugger.
