[Bug bootstrap/116730] build is broken when building in subdirectory of a subdirectory of the src directory

[himehaieto at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116730

--- Comment #43 from Hime Haieto <himehaieto at gmail dot com> ---
1) Yes, I had been building within a git worktree,
repodir/worktrees/<14.2_worktree>/build/votocon/.

2) The bad links I got looked nuts, like so:
../../../libbacktrace/../../../libbacktrace/../../../libbacktrace/atomic.c