Ok, now I understand what the man loop does. Is symlinks the manpages from `HOMEBREW_PREFIX/lib/node_modules/npm/man` to `#{share}/man`. And then your linker is clever enough to follow the symlinks in `#{share}/man` and link the man pages directly from `HOMEBREW_PREFIX/lib/node_modules/npm/man` into `HOMEBREW_PREFIX/share/man`.

The problem is, that we don't want the symlinks in `#{share}/man` in our bottle (or we get the issue discussed here). So we must either move the bottle generation before `post_install` or we symlink the man pages directly from `HOMEBREW_PREFIX/lib/node_modules/npm/man` to `HOMEBREW_PREFIX/share/man` and **not** via `#{share}/man` and homebrews build-in linker.