Commit graph

859 commits

Author SHA1 Message Date
Shea Levy
73874629ef nix-store --serve: Use dump instead of export
Also remove signing support

Signed-off-by: Shea Levy <shea@shealevy.com>
2014-02-08 00:13:33 -05:00
Shea Levy
188f96500b nix-store --serve: Don't fail if asked for info about non-valid path
Signed-off-by: Shea Levy <shea@shealevy.com>
2014-02-08 00:13:33 -05:00
Shea Levy
9488447594 nix-store --serve: Don't loop forever
nix-store --export takes a tmproot, which can only release by exiting.
Substituters don't currently work in a way that could take advantage of
the looping, anyway.

Signed-off-by: Shea Levy <shea@shealevy.com>
2014-02-08 00:13:32 -05:00
Shea Levy
3a38d0f356 Add the nix-store --serve command
This is essentially the substituter API operating on the local store,
which will be used by the ssh substituter. It runs in a loop rather than
just taking one command so that in the future nix will be able to keep
one connection open for multiple instances of the substituter.

Signed-off-by: Shea Levy <shea@shealevy.com>
2014-02-08 00:13:32 -05:00
Eelco Dolstra
d210cdc435 Fix assertion failure in ‘nix-store --load-db’
Namely:

  nix-store: derivations.cc:242: nix::Hash nix::hashDerivationModulo(nix::StoreAPI&, nix::Derivation): Assertion `store.isValidPath(i->first)' failed.

This happened because of the derivation output correctness check being
applied before the references of a derivation are valid.
2014-02-03 22:36:07 +01:00
Eelco Dolstra
d6582c04c1 Give a friendly error message if the DB directory is not writable
Previously we would say "error: setting synchronous mode: unable to
open database file" which isn't very helpful.
2014-02-01 16:57:38 +01:00
Eelco Dolstra
6ef32bddc1 Fix "make dist" 2014-02-01 14:38:12 +01:00
Eelco Dolstra
0c6d62cf27 Remove Automakefiles 2014-02-01 13:54:38 +01:00
Eelco Dolstra
16e7d69209 Update Makefile variable names 2014-02-01 13:54:38 +01:00
Eelco Dolstra
e0234dfddc Rename Makefile -> local.mk 2014-01-30 12:11:06 +01:00
Eelco Dolstra
94f9c14d52 Fix some clang warnings 2014-01-21 18:29:55 +01:00
Eelco Dolstra
81628a6ccc Merge branch 'master' into make
Conflicts:
	src/libexpr/eval.cc
2014-01-21 15:30:01 +01:00
Eelco Dolstra
b1db599dd0 Generate schema.sql.hh 2014-01-09 22:10:35 +01:00
Eelco Dolstra
b4c684e0f9 Update Makefiles 2014-01-09 16:53:47 +01:00
Eelco Dolstra
11cb4bfb25 Fix checking of NAR hashes
*headdesk*
*headdesk*
*headdesk*

So since commit 22144afa8d, Nix hasn't
actually checked whether the content of a downloaded NAR matches the
hash specified in the manifest / NAR info file.  Urghhh...
2014-01-08 17:35:49 +01:00
Domen Kožar
485f4740ee wording 2014-01-06 11:38:24 +01:00
Eelco Dolstra
a6add93d73 Garbage collector: Release locks on temporary root files
This allows processes waiting for such locks to proceed during the
trash deletion phase of the garbage collector.
2013-12-10 13:13:59 +01:00
Eelco Dolstra
c5b8fe3151 Print a trace message if a build fails due to the platform being unknown 2013-12-05 14:31:57 -05:00
Eelco Dolstra
7ce0e05ad8 Rename Makefile.new -> Makefile 2013-11-25 15:25:13 +00:00
Eelco Dolstra
2bd0fcc966 Use libnix as a prefix for all Nix libraries
In particular "libutil" was always a problem because it collides with
Glibc's libutil.  Even if we install into $(libdir)/nix, the linker
sometimes got confused (e.g. if a program links against libstore but
not libutil, then ld would report undefined symbols in libstore
because it was looking at Glibc's libutil).
2013-11-23 23:53:41 +00:00
Eelco Dolstra
90dfb37f14 Allow (dynamic) libraries to depend on other libraries 2013-11-23 20:11:02 +00:00
Eelco Dolstra
6b5f89f2cf Drop the dependency on Automake 2013-11-22 19:30:24 +00:00
Eelco Dolstra
754c05ed6c Rename $(here) to $(d) for brevity, and remove trailing slash 2013-11-22 16:45:52 +00:00
Eelco Dolstra
62e35cc3a8 Add ‘make dist’ support 2013-11-22 16:42:25 +01:00
Eelco Dolstra
b8e9efc476 New non-recursive, plain Make-based build system 2013-11-22 15:54:18 +01:00
Eelco Dolstra
709cbe4e76 Include <cstring> for memset
This should fix building on Illumos.
2013-11-22 10:00:43 +00:00
Eelco Dolstra
a478e8a7bb Remove nix-setuid-helper
AFAIK, nobody uses it, it's not maintained, and it has no tests.
2013-11-14 11:57:37 +01:00
Eelco Dolstra
89e6781cc5 Make function calls show up in stack traces again
Note that adding --show-trace prevents functions calls from being
tail-recursive, so an expression that evaluates without --show-trace
may fail with a stack overflow if --show-trace is given.
2013-11-12 12:51:59 +01:00
Eelco Dolstra
c086183843 For auto roots, show the intermediate link
I.e. "nix-store -q --roots" will now show (for example)

  /home/eelco/Dev/nixpkgs/result

rather than

  /nix/var/nix/gcroots/auto/53222qsppi12s2hkap8dm2lg8xhhyk6v
2013-10-22 11:39:10 +02:00
Eelco Dolstra
a737f51fd9 Retry all SQLite operations
To deal with SQLITE_PROTOCOL, we also need to retry read-only
operations.
2013-10-16 15:58:20 +02:00
Eelco Dolstra
ff02f5336c Fix a race in registerFailedPath()
Registering the path as failed can fail if another process does the
same thing after the call to hasPathFailed().  This is extremely
unlikely though.
2013-10-16 14:55:53 +02:00
Eelco Dolstra
4bd5282573 Convenience macros for retrying a SQLite transaction 2013-10-16 14:46:35 +02:00
Eelco Dolstra
bce14d0f61 Don't wrap read-only queries in a transaction
There is no risk of getting an inconsistent result here: if the ID
returned by queryValidPathId() is deleted from the database
concurrently, subsequent queries involving that ID will simply fail
(since IDs are never reused).
2013-10-16 14:36:53 +02:00
Eelco Dolstra
7cdefdbe73 Print a distinct warning for SQLITE_PROTOCOL 2013-10-16 14:27:36 +02:00
Eelco Dolstra
d05bf04444 Treat SQLITE_PROTOCOL as SQLITE_BUSY
In the Hydra build farm we fairly regularly get SQLITE_PROTOCOL errors
(e.g., "querying path in database: locking protocol").  The docs for
this error code say that it "is returned if some other process is
messing with file locks and has violated the file locking protocol
that SQLite uses on its rollback journal files."  However, the SQLite
source code reveals that this error can also occur under high load:

  if( cnt>5 ){
    int nDelay = 1;                      /* Pause time in microseconds */
    if( cnt>100 ){
      VVA_ONLY( pWal->lockError = 1; )
      return SQLITE_PROTOCOL;
    }
    if( cnt>=10 ) nDelay = (cnt-9)*238;  /* Max delay 21ms. Total delay 996ms */
    sqlite3OsSleep(pWal->pVfs, nDelay);
  }

i.e. if certain locks cannot be not acquired, SQLite will retry a
number of times before giving up and returing SQLITE_PROTOCOL.  The
comments say:

  Circumstances that cause a RETRY should only last for the briefest
  instances of time.  No I/O or other system calls are done while the
  locks are held, so the locks should not be held for very long. But
  if we are unlucky, another process that is holding a lock might get
  paged out or take a page-fault that is time-consuming to resolve,
  during the few nanoseconds that it is holding the lock.  In that case,
  it might take longer than normal for the lock to free.
  ...
  The total delay time before giving up is less than 1 second.

On a heavily loaded machine like lucifer (the main Hydra server),
which often has dozens of processes waiting for I/O, it seems to me
that a page fault could easily take more than a second to resolve.
So, let's treat SQLITE_PROTOCOL as SQLITE_BUSY and retry the
transaction.

Issue NixOS/hydra#14.
2013-10-16 14:19:59 +02:00
Eelco Dolstra
936f9d45ba Don't apply the CPU affinity hack to nix-shell (and other Perl programs)
As discovered by Todd Veldhuizen, the shell started by nix-shell has
its affinity set to a single CPU.  This is because nix-shell connects
to the Nix daemon, which causes the affinity hack to be applied.  So
we turn this off for Perl programs.
2013-09-06 16:36:56 +02:00
Eelco Dolstra
b29d3f4aee Only show trace messages when tracing is enabled 2013-09-02 12:01:04 +02:00
Eelco Dolstra
efe4289464 Add an option to limit the log output of builders
This is mostly useful for Hydra to deal with builders that get stuck
in an infinite loop writing data to stdout/stderr.
2013-09-02 11:58:18 +02:00
Ivan Kozik
34bb806f74 Fix typos, especially those that end up in the Nix manual 2013-08-26 11:15:22 +02:00
Gergely Risko
c6c024ca6f Fix personality switching from x86_64 to i686
On Linux, Nix can build i686 packages even on x86_64 systems.  It's not
enough to recognize this situation by settings.thisSystem, we also have
to consult uname().  E.g. we can be running on a i686 Debian with an
amd64 kernel.  In that situation settings.thisSystem is i686-linux, but
we still need to change personality to i686 to make builds consistent.
2013-08-26 11:12:35 +02:00
Eelco Dolstra
a583a2bc59 Run the daemon worker on the same CPU as the client
On a system with multiple CPUs, running Nix operations through the
daemon is significantly slower than "direct" mode:

$ NIX_REMOTE= nix-instantiate '<nixos>' -A system
real    0m0.974s
user    0m0.875s
sys     0m0.088s

$ NIX_REMOTE=daemon nix-instantiate '<nixos>' -A system
real    0m2.118s
user    0m1.463s
sys     0m0.218s

The main reason seems to be that the client and the worker get moved
to a different CPU after every call to the worker.  This patch adds a
hack to lock them to the same CPU.  With this, the overhead of going
through the daemon is very small:

$ NIX_REMOTE=daemon nix-instantiate '<nixos>' -A system
real    0m1.074s
user    0m0.809s
sys     0m0.098s
2013-08-07 14:02:04 +02:00
Eelco Dolstra
a4921b8ceb Revert "build-remote.pl: Enforce timeouts locally"
This reverts commit 69b8f9980f.

The timeout should be enforced remotely.  Otherwise, if the garbage
collector is running either locally or remotely, if will block the
build or closure copying for some time.  If the garbage collector
takes too long, the build may time out, which is not what we want.
Also, on heavily loaded systems, copying large paths to and from the
remote machine can take a long time, also potentially resulting in a
timeout.
2013-07-18 12:52:29 +02:00
Shea Levy
16591eb3cc Allow bind-mounting regular files into the chroot
mount(2) with MS_BIND allows mounting a regular file on top of a regular
file, so there's no reason to only bind directories. This allows finer
control over just which files are and aren't included in the chroot
without having to build symlink trees or the like.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-07-15 16:01:33 +02:00
Eelco Dolstra
aeb810b01e Garbage collector: Don't follow symlinks arbitrarily
Only indirect roots (symlinks to symlinks to the Nix store) are now
supported.
2013-07-12 14:03:36 +02:00
Eelco Dolstra
7ccd946407 Don't set $preferLocalBuild and $requiredSystemFeatures in builders
With C++ std::map, doing a comparison like ‘map["foo"] == ...’ has the
side-effect of adding a mapping from "foo" to the empty string if
"foo" doesn't exist in the map.  So we ended up setting some
environment variables by accident.
2013-06-20 18:07:27 +00:00
Eelco Dolstra
5558652709 Don't substitute derivations that have preferLocalBuild set
In particular this means that "trivial" derivations such as writeText
are not substituted, reducing the number of GET requests to the binary
cache by about 200 on a typical NixOS configuration.
2013-06-20 19:26:31 +02:00
Eelco Dolstra
1906cce6fc Increase SQLite's auto-checkpoint interval
Common operations like instantiating a NixOS system config no longer
fitted in 8192 pages, leading to more fsyncs.  So increase this limit.
2013-06-20 14:01:33 +00:00
Eelco Dolstra
9b11165aec Disable the copy-from-other-stores substituter
This substituter basically cannot work reliably since we switched to
SQLite, since SQLite databases may need write access to open them even
just for reading (and in WAL mode they always do).
2013-06-20 12:01:33 +02:00
Eelco Dolstra
22144afa8d Don't keep "disabled" substituters running
For instance, it's pointless to keep copy-from-other-stores running if
there are no other stores, or download-using-manifests if there are no
manifests.  This also speeds things up because we don't send queries
to those substituters.
2013-06-20 11:55:15 +02:00
Eelco Dolstra
1b6ee8f4c7 Allow hard links between the outputs of a derivation 2013-06-13 17:29:56 +02:00
Eelco Dolstra
cd49ee0897 Fix a security bug in hash rewriting
Before calling dumpPath(), we have to make sure the files are owned by
the build user.  Otherwise, the build could contain a hard link to
(say) /etc/shadow, which would then be read by the daemon and
rewritten as a world-readable file.

This only affects systems that don't have hard link restrictions
enabled.
2013-06-13 17:12:24 +02:00
Eelco Dolstra
1e2c7c04b1 Fix assertion failure in canonicalisePathMetaData() after hash rewriting
The assertion in canonicalisePathMetaData() failed because the
ownership of the path already changed due to the hash rewriting.  The
solution is not to check the ownership of rewritten paths.

Issue #122.
2013-06-13 17:12:06 +02:00
Eelco Dolstra
6cc2a8f8ed computeFSClosure: Only process the missing/corrupt paths
Issue #122.
2013-06-13 16:43:20 +02:00
Eelco Dolstra
f9ff67e948 In repair mode, update the hash of rebuilt paths
Otherwise subsequent invocations of "--repair" will keep rebuilding
the path.  This only happens if the path content differs between
builds (e.g. due to timestamps).
2013-06-13 14:46:07 +02:00
Eelco Dolstra
ca70fba0bf Remove obsolete EOF checks 2013-06-07 15:10:23 +02:00
Eelco Dolstra
5959c591a0 Process stderr from substituters while doing have/info queries 2013-06-07 15:02:14 +02:00
Eelco Dolstra
c5f9d0d080 Buffer reads from the substituter
This greatly reduces the number of system calls.
2013-06-07 14:00:23 +02:00
Eelco Dolstra
b09b87321c nix-store --export: Export paths in topologically sorted order
Fixes #118.
2013-05-23 14:55:36 -04:00
Eelco Dolstra
2ee9da9e22 In trace messages, don't print the output path
This doesn't work if there is no output named "out".  Hydra didn't use
it anyway.
2013-05-10 00:24:33 +02:00
Eelco Dolstra
6eba05613a Communicate build timeouts to Hydra 2013-05-09 18:39:04 +02:00
Eelco Dolstra
69b8f9980f build-remote.pl: Enforce timeouts locally
Don't pass --timeout / --max-silent-time to the remote builder.
Instead, let the local Nix process terminate the build if it exceeds a
timeout.  The remote builder will be killed as a side-effect.  This
gives better error reporting (since the timeout message from the
remote side wasn't properly propagated) and handles non-Nix problems
like SSH hangs.
2013-05-09 17:17:17 +02:00
Eelco Dolstra
470553bd05 Don't let stderr writes in substituters cause a deadlock 2013-05-01 13:21:39 +02:00
Eelco Dolstra
0374d94437 addAdditionalRoots(): Check each path only once 2013-04-26 12:07:25 +02:00
Eelco Dolstra
772b70952f Fix --timeout
I'm not sure if it has ever worked correctly.  The line "lastWait =
after;" seems to mean that the timer was reset every time a build
produced log output.

Note that the timeout is now per build, as documented ("the maximum
number of seconds that a builder can run").
2013-04-23 18:04:59 +02:00
Eelco Dolstra
934cf2d1f4 Nix daemon: respect build timeout from the client 2013-04-23 16:59:06 +02:00
Eelco Dolstra
258897c265 Complain if /homeless-shelter exists 2013-04-04 11:16:26 +02:00
Shea Levy
cc63db1dd5 makeStoreWritable: Ask forgiveness, not permission
It is surprisingly impossible to check if a mountpoint is a bind mount
on Linux, and in my previous commit I forgot to check if /nix/store was
even a mountpoint at all. statvfs.f_flag is not populated with MS_BIND
(and even if it were, my check was wrong in the previous commit).

Luckily, the semantics of mount with MS_REMOUNT | MS_BIND make both
checks unnecessary: if /nix/store is not a mountpoint, then mount will
fail with EINVAL, and if /nix/store is not a bind-mount, then it will
not be made writable. Thus, if /nix/store is not a mountpoint, we fail
immediately (since we don't know how to make it writable), and if
/nix/store IS a mountpoint but not a bind-mount, we fail at first write
(see below for why we can't check and fail immediately).

Note that, due to what is IMO buggy behavior in Linux, calling mount
with MS_REMOUNT | MS_BIND on a non-bind readonly mount makes the
mountpoint appear writable in two places: In the sixth (but not the
10th!) column of mountinfo, and in the f_flags member of struct statfs.
All other syscalls behave as if the mount point were still readonly (at
least for Linux 3.9-rc1, but I don't think this has changed recently or
is expected to soon). My preferred semantics would be for MS_REMOUNT |
MS_BIND to fail on a non-bind mount, as it doesn't make sense to remount
a non bind-mount as a bind mount.
2013-03-25 19:00:16 +01:00
Shea Levy
2c9cf50746 makeStoreWritable: Use statvfs instead of /proc/self/mountinfo to find out if /nix/store is a read-only bind mount
/nix/store could be a read-only bind mount even if it is / in its own filesystem, so checking the 4th field in mountinfo is insufficient.

Signed-off-by: Shea Levy <shea@shealevy.com>
2013-03-25 19:00:16 +01:00
Eelco Dolstra
bdd4646338 Revert "Prevent config.h from being clobbered"
This reverts commit 28bba8c44f.
2013-03-08 01:24:59 +01:00
Eelco Dolstra
28bba8c44f Prevent config.h from being clobbered 2013-03-07 23:55:55 +01:00
Eelco Dolstra
8057a192e3 Handle systems without lutimes() or lchown() 2013-02-28 19:55:09 +01:00
Eelco Dolstra
f45c731cd7 Handle symlinks properly
Now it's really brown paper bag time...
2013-02-28 14:51:08 +01:00
Eelco Dolstra
0111ba98ea Handle hard links to other files in the output 2013-02-27 17:18:41 +01:00
Eelco Dolstra
b008674e46 Refactoring: Split off the non-recursive canonicalisePathMetaData()
Also, change the file mode before changing the owner.  This prevents a
slight time window in which a setuid binary would be setuid root.
2013-02-27 16:42:19 +01:00
Eelco Dolstra
5526a282b5 Security: Don't allow builders to change permissions on files they don't own
It turns out that in multi-user Nix, a builder may be able to do

  ln /etc/shadow $out/foo

Afterwards, canonicalisePathMetaData() will be applied to $out/foo,
causing /etc/shadow's mode to be set to 444 (readable by everybody but
writable by nobody).  That's obviously Very Bad.

Fortunately, this fails in NixOS's default configuration because
/nix/store is a bind mount, so "ln" will fail with "Invalid
cross-device link".  It also fails if hard-link restrictions are
enabled, so a workaround is:

  echo 1 > /proc/sys/fs/protected_hardlinks

The solution is to check that all files in $out are owned by the build
user.  This means that innocuous operations like "ln
${pkgs.foo}/some-file $out/" are now rejected, but that already failed
in chroot builds anyway.
2013-02-26 02:30:19 +01:00
Ludovic Courtès
3e067ac11c Add `Settings::nixDaemonSocketFile'. 2013-02-19 10:19:18 +01:00
Ludovic Courtès
5ea138dc4b Enable chroot support on old glibc versions. 2013-02-19 10:19:11 +01:00
Eelco Dolstra
5e9c3da412 Only warn about SQLite being busy once
No need to get annoying.
2013-01-23 16:45:10 +01:00
Eelco Dolstra
536c85ea49 Store build logs in /nix/var/log/nix/drvs/<XX>
...where <XX> is the first two characters of the derivation.
Otherwise /nix/var/log/nix/drvs may become so large that we run into
all sorts of weird filesystem limits/inefficiences.  For instance,
ext3/ext4 filesystems will barf with "ext4_dx_add_entry:1551:
Directory index full!" once you hit a few million files.
2013-01-17 15:47:26 +01:00
Eelco Dolstra
e42df686f3 Delete a left-over trash directory before doing a GC 2013-01-05 00:13:29 +01:00
Eelco Dolstra
92926be2fe Fix "0 store paths deleted" message 2013-01-04 15:17:19 +01:00
Eelco Dolstra
b424d29d1b Open the database after removing immutable bits 2013-01-03 13:29:17 +01:00
Eelco Dolstra
def5160b61 Clear any immutable bits in the Nix store
Doing this once makes subsequent operations like garbage collecting
more efficient since we don't have to call makeMutable() first.
2013-01-03 12:59:23 +01:00
Eelco Dolstra
299141ecbd If a substitute closure is incomplete, build dependencies, then retry the substituter
Issue #77.
2013-01-02 12:38:28 +01:00
Eelco Dolstra
1b3a78a459 Automatically fall back if the references of a substitute are not substitutable
Fixes #77.
2013-01-02 12:00:26 +01:00
Eelco Dolstra
12f9129f60 nix-build: Support talking to old daemons
Fixes #76.
2012-12-29 23:21:46 +01:00
Eelco Dolstra
b7629778ef Allow mounting a path in a different location in the chroot
Fixes #24.
2012-12-29 23:04:02 +01:00
Eelco Dolstra
2754a07ead nix-store -q --roots: Respect the gc-keep-outputs/gc-keep-derivations settings
So if a path is not garbage solely because it's reachable from a root
due to the gc-keep-outputs or gc-keep-derivations settings, ‘nix-store
-q --roots’ now shows that root.
2012-12-20 18:41:44 +01:00
Eelco Dolstra
06f62defe6 Yet another rewrite of the garbage collector
But this time it's *obviously* correct!  No more segfaults due to
infinite recursions for sure, etc.

Also, move directories to /nix/store/trash instead of renaming them to
/nix/store/bla-gc-<pid>.  Then we can just delete /nix/store/trash at
the end.
2012-12-20 17:32:15 +01:00
Eelco Dolstra
e775d4d84f If gc-keep-derivations is set, only keep the actual deriver
This prevents zillions of derivations from being kept, and fixes an
infinite recursion in the garbage collector (due to an obscure cycle
that can occur with fixed-output derivations).
2012-12-19 15:33:09 +01:00
Eelco Dolstra
fbf0b2fa45 Kill the build hook rather than shutting it down cleanly
Waiting for the hook to shut down cleanly sometimes seems to lead to
hangs.
2012-12-19 11:47:42 +01:00
Eelco Dolstra
228ea7c2f9 Revert brain fart
This reverts commit cc511fd65b.
2012-12-18 20:43:47 +01:00
Eelco Dolstra
cc511fd65b Check for potential infinite select() loops when building 2012-12-18 18:50:05 +01:00
Eelco Dolstra
772778c0ec On SQLITE_BUSY, wait a random amount of time
If all contending processes wait a fixed amount of time (100 ms),
there is a good probability that they'll just collide again.
2012-12-11 11:49:42 +01:00
Eelco Dolstra
8b8ee53bc7 Add builtin constants ‘langVersion’ and ‘nixVersion’
The integer constant ‘langVersion’ denotes the current language
version.  It gets increased every time a language feature is
added/changed/removed.  It's currently 1.

The string constant ‘nixVersion’ contains the current Nix version,
e.g. "1.2pre2980_9de6bc5".
2012-11-27 13:29:55 +01:00
Eelco Dolstra
5943f41b8b queryMissing(): Handle partially valid derivations 2012-11-26 18:25:12 +01:00
Eelco Dolstra
8d8d47abd2 Only substitute wanted outputs of a derivation
If a derivation has multiple outputs, then we only want to download
those outputs that are actuallty needed.  So if we do "nix-build -A
openssl.man", then only the "man" output should be downloaded.
Likewise if another package depends on ${openssl.man}.

The tricky part is that different derivations can depend on different
outputs of a given derivation, so we may need to restart the
corresponding derivation goal if that happens.
2012-11-26 17:15:09 +01:00
Eelco Dolstra
46a369ad95 Make "nix-build -A <derivation>.<output>" do the right thing
For example, given a derivation with outputs "out", "man" and "bin":

  $ nix-build -A pkg

produces ./result pointing to the "out" output;

  $ nix-build -A pkg.man

produces ./result-man pointing to the "man" output;

  $ nix-build -A pkg.all

produces ./result, ./result-man and ./result-bin;

  $ nix-build -A pkg.all -A pkg2

produces ./result, ./result-man, ./result-bin and ./result-2.
2012-11-26 15:39:10 +01:00
Eelco Dolstra
f794465ca8 Disable use of vfork()
vfork() is just too weird.  For instance, in this build:

  http://hydra.nixos.org/build/3330487

the value fromHook.writeSide becomes corrupted in the parent, even
though the child only reads from it.  At -O0 the problem goes away.
Probably the child is overriding some spilled temporary variable.

If I get bored I may implement using posix_spawn() instead.
2012-11-15 19:35:18 +01:00
Eelco Dolstra
8541d27fce Don't use std::cerr in a few places
Slightly scared of using std::cerr in a vforked process...
2012-11-15 15:01:02 +01:00