I don't know if this was discussed at the time ALTER SYSTEM was
implemented, but I have just discovered that if postgresql.auto.conf is
a symlink to a file elsewhere, ALTER SYSTEM will happily break that link
and write its own local copy. That strikes me as rather unfriendly. Why
not just truncate the file rather than unlink it as it's being
rewritten? Even if we don't want to do that a warning in the docs might
help users avoid the "mistake" I just made.
cheers
andrew