value; this potentially dangerous feature enables better
sharing for those paths for which the content is known in
advance (e.g., because a content hash is given).
* Fast builds: if we can expand all output paths of a derive
expression, we don't have to build.
* A function to find all Nix expressions whose output ids are
completely contained in some set. Useful for uploading relevant Nix
expressions to a shared cache.
number of bytes, e.g., in case of a signal like SIGSTOP.
This caused `nix --dump' to fail sometimes.
Note that this bug went unnoticed because the call to `nix
--dump' is in a pipeline, and the shell ignores non-zero
exit codes from all but the last element in the pipeline.
Is there any way to check the result of the initial elements
in the pipeline? (In other words, is it at all possible to
write reliable shell scripts?)
input path is referenced in an output paths, we also have to
add all ids referenced by that input path.
* Better debug assertions to catch these sorts of errors.
This is not entirely trivial since this introduces the possibility
of mutual recursion.
* Made normal forms self-contained.
* Use unique ids, not content hashes, for content referencing.
Unifying substitutes and successors isn't very feasible for now,
since substitutes are only used when no path with a certain is
known. Therefore, a normal form of some expression stored as a
substitute would not be used unless the expression itself was
missing.
hash for which no local expansion is available, Nix can execute a
`substitute' which should produce a path with such a hash.
This is policy-free since Nix does not in any way specify how the
substitute should work, i.e., it's an arbitrary (unnormalised)
fstate expression. For example, `nix-pull' registers substitutes
that fetch Nix archives from the network (through `wget') and unpack
them, but any other method is possible as well. This is an
improvement over the old Nix sharing scheme, which had a policy
(fetching through `wget') built in.
The sharing scheme doesn't work completely yet because successors
from fstate rewriting have to be registered on the receiving side.
Probably the whole successor stuff can be folded up into the
substitute mechanism; this would be a nice simplification.
archives (using the package in corepkgs/nar).
* queryPathByHash -> expandHash, and it takes an argument specifying
the target path (which may be empty).
* Install the core Fix packages in $prefix/share/fix. TODO: bootstrap
Nix and install Nix as a Fix package.
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.
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.
