The symlink is created in bindir (/usr/bin), and points to a binary
which lives in rootlibexecdir (/lib/systemd or /usr/lib/systemd). A
relative symlink does not work here.
bus-proxyd-install-hook:
$(AM_V_at)$(MKDIR_P) $(DESTDIR)$(bindir)
- $(AM_V_LN)$(LN_S) -f ../lib/systemd/systemd-bus-proxyd $(DESTDIR)$(bindir)/systemd-stdio-bridge
+ $(AM_V_LN)$(LN_S) -f $(rootlibexecdir)/systemd-bus-proxyd $(DESTDIR)$(bindir)/systemd-stdio-bridge
bus-proxyd-uninstall-hook:
rm -f $(DESTDIR)$(bindir)/systemd-stdio-bridge