a mapping from the hash to a url has been registered through `nix
regurl'.
* Bug fix in nix: don't pollute stdout when running tar, it made
nix-switch barf.
* Bug fix in nix-push-prebuilts: don't create a subdirectory on the
target when rsync'ing.
sharing package directories (i.e., the result of building a Nix
descriptor).
`nix-pull-prebuilts' obtains a list of all known prebuilts by
consulting the paths and URLs specified in
$prefix/etc/nix/prebuilts.conf. The mappings ($pkghash,
$prebuilthash) and ($prebuilthash, $location) are registered with
Nix so that it can use the prebuilt with hash $prebuilthash when
installing a package with hash $pkghash by downloading and unpacking
$location.
`nix-push-prebuilts' creates prebuilts for all packages for which no
prebuilt is known to exist. It can then optionally upload these
to the network through rsync.
`nix-[pull|push]-prebuilts' just provide a policy. Nix provides the
mechanism through the `nix [export|regprebuilt|regurl]' commands.
* Conditionals and variables in Fix expressions. This allows, e.g.,
Descr(
[ Bind("pkgId", "subversion-0.21.0")
, Bind("httpsClient", Bool(True))
, Bind("httpServer", Bool(True))
, Bind("ssl", If(Var("httpsClient"), Fix("./openssl-0.9.7b.fix"), ""))
, Bind("httpd", If(Var("httpServer"), Fix("./httpd-2.0.45.fix"), ""))
...
])
which introduces domain feature variables httpsClient and httpServer
(i.e., whether Subversion is built with https client and webdav
server support); the values of the variables influences package
dependencies and the build scripts.
The next step is to allow that packages can express constraints on
each other. E.g., StrategoXT is dependent on an ATerm library with
the "gcc" variant enabled. In fact, this may cause several
Nix instantiations to be created from a single Fix descriptor. If
possible, Fix should try to find the least set of instantiations
that obeys the constraints.
doesn't actually delete any packages, it just prints their
descriptor hashes. So we can do
nix info $(nix-collect-garbage)
to print out the ids of the packages that would be deleted, and
nix delpkg $(nix-collect-garbage)
to actually delete them.
This allows us to find out all `live' packages on the system by
doing
nix closure $(cat /nix/var/nix/links/*.hash)
which will print out the activated configurations and all packages
referenced by them. We could then garbage collect unused packages
by deleting the difference between `nix listinst' and the set
returned by `nix closure ...'.
descriptors generated out of Fix descriptors specified on the
command line. This allows us to say:
nix-switch $(fix -i ./test/fixdescriptors/system.fix)
build action for `system' packages (like system.fix) that have
dependencies on all packages we want to activate.
So the command sequence to switch to a new activation configuration
of the system would be:
$ fix -i .../fixdescriptors/system.fix
...
system.fix -> 89cf4713b37cc66989304abeb9ea189f
$ nix-switch 89cf4713b37cc66989304abeb9ea189f
* A nix-profile.sh script that can be included in .bashrc.
packages (i.e., the packages that should appear in the user's $PATH,
and so on). Based on this list, the script nix-populate creates a
hierarchy of symlinks to the relevant files in those packages (e.g.,
for pkg/bin and pkg/lib).
A nice property of nix-populate is that on each run it creates a
*new* tree, rather than updating the old one. It then atomically
switches over to the new tree. This allows atomic upgrades or
rollbacks on the set of activated packages.
