whether we want to upgrade if the current version is less than the
available version (default), when it is less or equal, or always.
* Added a flag `--dry-run' to show what would happen in `--install',
`--uninstall', and `--upgrade', without actually performing the
operation.
of the current profile, e.g.,
$ nix-env --list-generations
...
39 2004-02-02 17:53:53
40 2004-02-02 17:55:18
41 2004-02-02 17:55:41
42 2004-02-02 17:55:50 (current)
$ nix-env --switch-generation 39
$ ls -l /nix/var/nix/profiles/default
... default -> default-39-link
* Also a command `--rollback' which is just a convenience operation to
rollback to the oldest generation younger than the current one.
Note that generations properly form a tree. E.g., if after
switching to generation 39, we perform an installation action,
a generation 43 is created which is a descendant of 39, not 42. So
a rollback from 43 ought to go back to 39. This is not currently
implemented; generations form a linear sequence.
default -> default-94-link
default-82-link -> /nix/store/cc4480...
default-83-link -> /nix/store/caeec8...
...
default-94-link -> /nix/store/2896ca...
experimental -> experimental-2-link
experimental-1-link -> /nix/store/cc4480...
experimental-2-link -> /nix/store/a3148f...
* `--profile' / `-p' -> `--switch-profile' / `-S'
* `--link' / `-l' -> `--profile' / `-p'
* The default profile is stored in $prefix/var/nix/profiles.
$prefix/var/nix/links is gone. Profiles can be stored anywhere.
* The current profile is now referenced from ~/.nix-profile, not
~/.nix-userenv.
* The roots to the garbage collector now have extension `.gcroot', not
`.id'.
other attribute sets, rather than the current scope. E.g.,
{inherit (pkgs) gcc binutils;}
is equivalent to
{gcc = pkgs.gcc; binutils = pkgs.binutils;}
I am not so happy about the syntax.
parser (roughly 80x faster).
The absolutely latest version of Bison (1.875c) is required for
reentrant GLR support, as well as a recent version of Flex (say,
2.5.31). Note that most Unix distributions ship with the
prehistoric Flex 2.5.4, which doesn't support reentrancy.
Nix. This is to prevent Berkeley DB from becoming wedged.
Unfortunately it is not possible to throw C++ exceptions from a
signal handler. In fact, you can't do much of anything except
change variables of type `volatile sig_atomic_t'. So we set an
interrupt flag in the signal handler and check it at various
strategic locations in the code (by calling checkInterrupt()).
Since this is unlikely to cover all cases (e.g., (semi-)infinite
loops), sometimes SIGTERM may now be required to kill Nix.
the output path of a derivation, not the path of its store
expression. This ensures that changes that affect the path of the
store expression but not the output path, do not affect the
`installed' state of a derivation.
it automatically removes log files when they are no longer needed.
*** IMPORTANT ***
If you have an existing Nix installation, you must checkpoint the
Nix database to prevent recent transactions from being undone. Do
the following:
- optional: make a backup of $prefix/var/nix/db.
- run `db_checkpoint' from Berkeley DB 4.1:
$ db_checkpoint -h $prefix/var/nix/db -1
- optional (?): run `db_recover' from Berkeley DB 4.1:
$ db_recover -h $prefix/var/nix/db
- remove $prefix/var/nix/db/log* and $prefix/var/nix/db/__db*
path of the Nix expression to be used with the import, upgrade, and
query commands. For instance,
$ nix-env -I ~/nixpkgs/pkgs/system/i686-linux.nix
$ nix-env --query --available [aka -qa]
sylpheed-0.9.7
bison-1.875
pango-1.2.5
subversion-0.35.1
...
$ nix-env -i sylpheed
$ nix-env -u subversion
There can be only one default at a time.
* If the path to a Nix expression is a symlink, follow the symlink
prior to resolving relative path references in the expression.
the symlink ~/.nix-userenv to the given argument (which defaults to
.../links/current). /etc/profile.d/nix-profile creates this symlink
if it doesn't exist yet. Example use:
$ nix-env -l my_profile -i foo.nix subversion quake
$ nix-env -p my_profile
I don't like the term "profile". Let's deprecate it :-)
nix-env -u foo.nix strategoxt
to replace the installed `strategoxt' derivation with the one from `foo.nix', if
the latter has a higher version number. This is a no-op if `strategoxt' is not
installed. Wildcards are also accepted, so
nix-env -u foo.nix '*'
will replace any installed derivation with newer versions from `foo.nix', if
available.
The notion of "version number" is somewhat ad hoc, but should be useful in most
cases, as evidenced by the following unit tests for the version comparator:
TEST("1.0", "2.3", -1);
TEST("2.1", "2.3", -1);
TEST("2.3", "2.3", 0);
TEST("2.5", "2.3", 1);
TEST("3.1", "2.3", 1);
TEST("2.3.1", "2.3", 1);
TEST("2.3.1", "2.3a", 1);
TEST("2.3pre1", "2.3", -1);
TEST("2.3pre3", "2.3pre12", -1);
TEST("2.3a", "2.3c", -1);
TEST("2.3pre1", "2.3c", -1);
TEST("2.3pre1", "2.3q", -1);
(-1 = less, 0 = equal, 1 = greater)
* A new verbosity level `lvlInfo', between `lvlError' and `lvlTalkative'. This is
the default for `nix-env', so without any `-v' flags users should get useful
output, e.g.,
$ nix-env -u foo.nix strategoxt
upgrading `strategoxt-0.9.2' to `strategoxt-0.9.3'
turned out to be a huge performance bottleneck (the text to printed
would always be evaluated, even when it was above the verbosity
level). This reduces fix-ng execution time by over 50%.
gprof(1) is very useful. :-)
The ATerm library doesn't search the heap for pointers to ATerms
when garbage collecting. As a result, C++ containers such as
`map<ATerm, ATerm>' will cause pointer to be hidden from the garbage
collector, causing crashes. Instead, we now use ATermTables.
writes stdout/stderr of the builder to ${prefix}/var/log/nix/x,
where x is the file name of the derivation expression, e.g.,
/nix/var/log/nix/54256391624be04fcb426048ae3ea0a4-d-pan-0.14.2.nix
Note that consecutive builds of the same expression overwrite,
rather than append to, existing log files.
* Fixed a segfault caused by the buffering of stderr.
* Fix now allows the specification of the full output path. This
should be used with great care, since it by-passes the normal hash
generation.
* Incremented the version number to 0.4 (prerelease).
log on commit. This means that there is a small change that some
transactions may be rolled back in case of a system crash, but this
should not be a problem (it merely might cause some expression
realisations to be rolled back), and it vastly improves performance.
* Upgraded to ATerm 2.0.5 (which also includes Armijn's 64-bit
patches).
* Point $HOME to a non-existing path when building to prevent certain tools (such as
wget) from falling back on /etc/passwd to locate the home directory (which we
don't want them to look at since it's not declared as an input).
keys to reference slice elements, e.g.,
Slice(["1ef7..."], [("/nix/store/1ef7...-foo", "1ef7", ["8c99..."]), ...])
This was wrong, since ids represent contents, not locations. Therefore we
now have:
Slice(["/nix/store/1ef7..."], [("/nix/store/1ef7...-foo", "1ef7", ["/nix/store/8c99-..."]), ...])
* Fix a bug in the computation of slice closures that could cause slice
elements to be duplicated.
("srcs", [Relative("foo/bar.c"), Relative("foo/baz.h")])
The result is an environment variable that contains the path names of the
inputs separated by spaces (so this is not safe for values containing
spaces).
builder using the `args' binding:
("args", ["bla", True, IncludeFix("aterm/aterm.fix")])
Note that packages can also be declared as inputs by specifying them
in the argument list.
process is already holding a lock on a path, it may acquire the lock
again without blocking or failing). (This might be dangerous, not
sure). Necessary for fast builds to work.
normal form in a single transaction to ensure that if we crash,
either everything is registered or nothing is. This is for
recoverability: unregistered paths in the store can be deleted
arbitrarily, while registered paths can only be deleted by running
the garbage collector.
* Open all database tables (Db objects) at initialisation time, not
every time they are used. This is necessary because tables have to
outlive all transactions that refer to them.
Renamed `fstateRefs' to `fstateRequisites'. The semantics of this
function is that it returns a list of all paths necessary to realise
a given expression. For a derive expression, this is the union of
requisites of the inputs; for a slice expression, it is the path of
each element in the slice. Also included are the paths of the
expressions themselves. Optionally, one can also include the
requisites of successor expressions (to recycle intermediate
results).
* `nix-switch' now distinguishes between an expression and its normal
form. Usually, only the normal form is registered as a root of the
garbage collector. With the `--source-root' flag, it will also
register the original expression as a root.
* `nix-collect-garbage' now has a flag `--keep-successors' which
causes successors not to be included in the list of garbage paths.
* `nix-collect-garbage' now has a flag `--invert' which will print all
paths that should *not* be garbage collected.
up to the given verbosity levels. These currently are:
lvlError = 0,
lvlNormal = 5,
lvlDebug = 10,
lvlDebugMore = 15
although only lvlError and lvlDebug are actually used right now.
substituting for (obvious, really).
* For greater efficiency, nix-pull/unnar will place the output in a
path that is probably the same as what is actually needed, thus
preventing a path copy.
* Even if a output id is given in a Fix package expression, ensure
that the resulting Nix derive expression has a different id. This
is because Nix expressions that are semantically equivalent (i.e.,
build the same result) might be different w.r.t. efficiency or
divergence. It is absolutely vital for the substitute mechanism
that such expressions are not used interchangeably.
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.
