again. (After the previous substituter mechanism refactoring I
didn't update the code that obtains the references of substitutable
paths.) This required some refactoring: the substituter programs
are now kept running and receive/respond to info requests via
stdin/stdout.
it only does something if $NIX_OTHER_STORES (not really a good
name...) is set.
* Do globbing on the elements of $NIX_OTHER_STORES. E.g. you could
set it to /mnts/*/nix or something.
* Install substituters in libexec/nix/substituters.
stores (typically remote Nix stores mounted via e.g. NFS, or the Nix
store on the NixOS installation CD). Example use:
$ sshfs foo@example.org:/ /mnt
$ NIX_OTHER_STORES=/mnt/nix \
NIX_SUBSTITUTERS=.../copy-from-other-stores.pl \
nix-env -i foo
This will be especially useful for the installation CD since it
doesn't require a manifest for the CD contents.
