Commit graph

177 commits

Author SHA1 Message Date
Eelco Dolstra
0321ef9bb2 Ugly hack to allow --argstr values starting with a dash
Fixes #265.
2014-05-23 14:43:58 +02:00
Eelco Dolstra
90dc50b07c restoreSIGPIPE(): Fill in sa_mask
Issue #231.
2014-03-29 20:20:14 +01:00
Shea Levy
64e23d0a38 Add download-via-ssh substituter
This substituter connects to a remote host, runs nix-store --serve
there, and then forwards substituter commands on to the remote host and
sends their results to the calling program. The ssh-substituter-hosts
option can be specified as a list of hosts to try.

This is an initial implementation and, while it works, it has some
limitations:

* Only the first host is used
* There is no caching of query results (all queries are sent to the
  remote machine)
* There is no informative output (such as progress bars)
* Some failure modes may cause unhelpful error messages
* There is no concept of trusted-ssh-substituter-hosts

Signed-off-by: Shea Levy <shea@shealevy.com>
2014-02-08 00:13:33 -05:00
Eelco Dolstra
81628a6ccc Merge branch 'master' into make
Conflicts:
	src/libexpr/eval.cc
2014-01-21 15:30:01 +01:00
Eelco Dolstra
769f662165 nix-shell: Don't warn about the lack of a GC root 2013-12-20 12:19:10 +00:00
Eelco Dolstra
5a1114ecdb Drop the dependency on libgc in libmain
Instead, libexpr now depends on libgc.  This means commands like
nix-store that don't do any evaluation no longer require libgc.
2013-11-23 20:19:36 +00:00
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
28e0742966 Report OOM errors better 2013-10-02 14:34:36 +02:00
Eelco Dolstra
70e68e0ec6 Detect stack overflows
Previously, if the Nix evaluator gets a stack overflow due to a deep
or infinite recursion in the Nix expression, the user gets an
unhelpful message ("Segmentation fault") that doesn't indicate that
the problem is in the user's code rather than Nix itself.  Now it
prints:

  error: stack overflow (possible infinite recursion)

This only works on x86_64-linux and i686-linux.

Fixes #35.
2013-07-30 23:37:10 +02:00
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
dadf7a5b46 build-remote: Use the --quiet flag
‘--option verbosity 0’ doesn't actually do anything.
2013-02-19 16:56:31 +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
9de6bc5d05 nix-store -r: Add ‘--ignore-unknown’ flag
This flag causes paths that do not have a known substitute to be
quietly ignored.  This is mostly useful for Charon, allowing it to
speed up deployment by letting a machine use substitutes for all
substitutable paths, instead of uploading them.  The latter is
frequently faster, e.g. if the target machine has a fast Internet
connection while the source machine is on a slow ADSL line.
2012-11-20 00:27:25 +01:00
Eelco Dolstra
522ecab9b8 Drop support for running nix-worker in "slave" mode
AFAIK nobody uses this, setuid binaries are evil, and there is no good
reason why people can't just run the daemon.
2012-10-03 17:30:45 -04:00
Eelco Dolstra
a562d544d8 When ‘--help’ is given, just run ‘man’ to show the manual page
I.e. do what git does.  I'm too lazy to keep the builtin help text up
to date :-)

Also add ‘--help’ to various commands that lacked it
(e.g. nix-collect-garbage).
2012-10-03 16:40:09 -04:00
Eelco Dolstra
e94806d030 Merge branch 'master' into no-manifests 2012-08-27 11:09:07 -04:00
Eelco Dolstra
a9e6752bbd Include the output name in the GC root link
Output names are now appended to resulting GC symlinks, e.g. by
nix-build.  For backwards compatibility, if the output is named "out",
nothing is appended.  E.g. doing "nix-build -A foo" on a derivation
that produces outputs "out", "bin" and "dev" will produce symlinks
"./result", "./result-bin" and "./result-dev", respectively.
2012-08-24 16:58:11 -04:00
Eelco Dolstra
89a8207029 Add an option ‘build-fallback’ (equivalent to the --fallback flag) 2012-07-31 17:56:02 -04:00
Eelco Dolstra
97421eb5ec Refactor settings processing
Put all Nix configuration flags in a Settings object.
2012-07-30 19:55:41 -04:00
Eelco Dolstra
d50d7a2874 Whitespace 2012-07-30 17:13:25 -04:00
Eelco Dolstra
bd50c01972 Ensure that Perl processes delete their entry in the temproots directory
By moving the destructor object to libstore.so, it's also run when
download-using-manifests and nix-prefetch-url exit.  This prevents
them from cluttering /nix/var/nix/temproots with stale files.
2012-03-13 17:07:49 +01:00
Eelco Dolstra
1d487dc6a6 nix-worker: put the pid of the caller in argv[1]
This is useful for debugging.
2012-03-05 19:19:29 +01:00
Eelco Dolstra
893cac1402 * Remove the terminate handler, which was only really needed because
of Berkeley DB (see r8632).
2011-12-14 22:41:10 +00:00
Eelco Dolstra
b1eb8f4249 * Get rid of some superfluous error messages if a substituter fails.
* Say "fetch" instead of "substitute".
2011-11-29 13:00:41 +00:00
Eelco Dolstra
993fa94fb4 * Move initialisation of variables like nixConfDir from libmain to
libstore so that the Perl bindings can use it as well.  It's vital
  that the Perl bindings use the configuration file, because otherwise
  nix-copy-closure will fail with a ‘database locked’ message if the
  value of ‘use-sqlite-wal’ is changed from the default.
2011-11-22 17:28:41 +00:00
Eelco Dolstra
e6cb3d0a0d * Added a command ‘nix-store --verify-paths PATHS’ to check whether
the contents of any of the given store paths have been modified.
  E.g.

    $ nix-store --verify-path $(nix-store -qR /var/run/current-system)
    path `/nix/store/m2smyiwbxidlprfxfz4rjlvz2c3mg58y-etc' was modified! expected hash `fc87e271c5fdf179b47939b08ad13440493805584b35e3014109d04d8436e7b8', got `20f1a47281b3c0cbe299ce47ad5ca7340b20ab34246426915fce0ee9116483aa'

  All paths are checked; the exit code is 1 if any path has been
  modified, 0 otherwise.
2011-09-06 12:06:30 +00:00
Eelco Dolstra
93227ff65c * Eliminate all uses of the global variable ‘store’ from libstore.
This should also fix:

    nix-instantiate: ./../boost/shared_ptr.hpp:254: T* boost::shared_ptr<T>::operator->() const [with T = nix::StoreAPI]: Assertion `px != 0' failed.

  which was caused by hashDerivationModulo() calling the ‘store’
  object (during store upgrades) before openStore() assigned it.
2011-08-31 21:11:50 +00:00
Ludovic Courtès
5c9e9f732d Add support for the build-timeout' and --timeout' options. 2011-06-30 15:19:13 +00:00
Eelco Dolstra
5a6b039802 * Don't call GC_expand_hp unless we're actually using the garbage
collector.
2011-02-09 22:59:50 +00:00
Eelco Dolstra
d787285af9 * nix-instantiate: return exit status 100 to denote a permanent build
failure.  The build hook can use this to distinguish between
  transient and permanent failures on the remote side.
2010-12-13 16:53:23 +00:00
Eelco Dolstra
bdf089f463 * Before a build, show the disk space that the downloaded store paths
will approximately require.
2010-11-17 14:31:42 +00:00
Eelco Dolstra
fb9368b5a0 * Sync with the trunk. 2010-11-16 12:49:47 +00:00
Eelco Dolstra
26def5392f * Document Boehm GC support. 2010-10-29 14:44:02 +00:00
Eelco Dolstra
14fbf85380 * Set libgc's initial heap size to 384 MiB to prevent garbage
collection in most cases (and therefore its performance overhead).
2010-10-29 13:11:50 +00:00
Eelco Dolstra
e11e6fb1c6 * Handle out of memory condition. 2010-10-28 12:29:40 +00:00
Eelco Dolstra
80e722278c * When using the build hook, distinguish between the stderr of the
hook script proper, and the stdout/stderr of the builder.  Only the
  latter should be saved in /nix/var/log/nix/drvs.
* Allow the verbosity to be set through an option.
* Added a flag --quiet to lower the verbosity level.
2010-08-30 14:53:03 +00:00
Eelco Dolstra
750be19ae8 * Remove "auto" and "guess" as synonyms for 0 in the handling of
build-cores and --cores.  They're superfluous and just complicate
  the parsing.
2010-08-04 12:23:59 +00:00
Peter Simons
8b7f8b56f1 Added support for passing an (impure) NIX_BUILD_CORES variable to build expressions.
This patch adds the configuration file variable "build-cores" and the
command line argument "--cores". These settings specify the number of
CPU cores to utilize for parallel building within a job, i.e. by passing
an appropriate "-j" flag to GNU Make. The default value is 1, which
means that parallel building is *disabled*. If the number of build cores
is specified as 0 (synonymously: "guess" or "auto"), then the actual
value is supposed to be auto-detected by builders at run-time, i.e by
calling the nproc(1) utility from coreutils.

The environment variable $NIX_BUILD_CORES is available to builders, but
the contents of that variable does *not* influence the hash that goes
into the $out store path, i.e. the number of build cores to be utilized
can be changed at will without requiring any re-builds.
2010-06-23 14:34:08 +00:00
Eelco Dolstra
f3b8833a48 * Drop the dependency on the ATerm library. 2010-04-19 14:51:58 +00:00
Eelco Dolstra
efc7a579e8 * Don't use the ATerm library for parsing/printing .drv files. 2010-04-19 13:46:58 +00:00
Eelco Dolstra
10e8b1fd15 * Finished the ATerm-less parser. 2010-04-12 23:33:23 +00:00
Eelco Dolstra
4d6ad5be17 * Don't use ATerms for the abstract syntax trees anymore. Not
finished yet.
2010-04-12 18:30:11 +00:00
Eelco Dolstra
4e17be7981 * Revert r19797, and use a simpler solution: just don't monitor build
hooks for silence.  It's unnecessary because the remote nix-store
  command is already monitoring the real build.
2010-02-03 21:38:41 +00:00
Eelco Dolstra
f859a8d3c3 * While waiting for a lock, print a sign of life every 5 minutes.
This prevents remote builders from being killed by the
  `max-silent-time' inactivity monitor while they are waiting for a
  long garbage collection to finish.  This happens fairly often in the
  Hydra build farm.
2010-02-03 21:22:57 +00:00
Eelco Dolstra
f0c0277970 * On startup, set the default SIGCHLD handler. This is so that Nix
works correctly in weird environments where the SIGCHLD handler is
  set to "ignore".
2010-01-12 12:22:38 +00:00
Eelco Dolstra
9b8fda796b * Templatise getIntArg / string2Int. 2009-11-24 12:26:25 +00:00
Eelco Dolstra
f2c3fc5191 * Don't show trace information by default (`--show-trace' to enable).
NixOS evaluation errors in particular look intimidating and
  generally aren't very useful.  Ideally the builtins.throw messages
  should be self-contained.
2009-06-30 13:28:29 +00:00
Eelco Dolstra
60cb7de336 * Allow options from the Nix config file to be overriden from the
command line (e.g. "--option build-use-chroot true").
2009-02-27 11:04:41 +00:00
Eelco Dolstra
652817046b * Revert r13150: now that we use private namespaces for the chroot, we
don't have to put the chroot in /nix/var/nix/chroots anymore.
  They're back in /tmp now.
2008-12-11 17:52:34 +00:00
Eelco Dolstra
a519bb0635 * Some somewhat ad hoc mechanism to allow the build farm to monitor
build progress.
2008-11-12 11:08:27 +00:00
Eelco Dolstra
709b55ee02 * Put the chroots under /nix/var/nix/chroots to reduce the risk of
disasters involving `rm -rf' on bind mounts.  Will try the
  definitive fix (per-process mounts, apparently possible via the
  CLONE_NEWNS flag in clone()) some other time.
2008-10-29 15:34:48 +00:00
Eelco Dolstra
a1d310b6b5 * `nix-store --realise': print what paths will be built/downloaded,
just like nix-env.
* `nix-store --realise': --dry-run option.
2008-08-04 13:44:46 +00:00
Eelco Dolstra
03427e76f1 * querySubstitutablePathInfo: work properly when run via the daemon.
* --dry-run: print the paths that we don't know how to build/substitute.
2008-08-04 11:44:50 +00:00
Eelco Dolstra
8bc591a6f0 * Use the copy-from-other-stores substituter by default. Of course,
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.
2008-07-18 13:05:10 +00:00
Eelco Dolstra
5af84139a8 * --max-freed: support values >= 4 GB. 2008-06-18 15:20:33 +00:00
Eelco Dolstra
d3aa183beb * Garbage collector: option `--max-freed' to stop after at least N
bytes have been freed, `--max-links' to stop when the Nix store
  directory has fewer than N hard links (the latter being important
  for very large Nix stores on filesystems with a 32000 subdirectories
  limit).
2008-06-18 14:20:16 +00:00
Eelco Dolstra
f351834f77 * nix-worker: clean up the temporary root for the worker processes
in /nix/var/nix/temproots.
2008-06-14 16:03:02 +00:00
Eelco Dolstra
c370755583 * Flag `--no-build-hook' to disable distributed builds.
* queryDeriver in daemon mode: don't barf if the other side returns an
  empty string (which means there is no deriver).
2007-11-16 16:15:26 +00:00
Eelco Dolstra
9e975458b4 * Get rid of the substitutes database table (NIX-47). Instead, if we
need any info on substitutable paths, we just call the substituters
  (such as download-using-manifests.pl) directly.  This means that
  it's no longer necessary for nix-pull to register substitutes or for
  nix-channel to clear them, which makes those operations much faster
  (NIX-95).  Also, we don't have to worry about keeping nix-pull
  manifests (in /nix/var/nix/manifests) and the database in sync with
  each other.

  The downside is that there is some overhead in calling an external
  program to get the substitutes info.  For instance, "nix-env -qas"
  takes a bit longer.

  Abolishing the substitutes table also makes the logic in
  local-store.cc simpler, as we don't need to store info for invalid
  paths.  On the downside, you cannot do things like "nix-store -qR"
  on a substitutable but invalid path (but nobody did that anyway).

* Never catch interrupts (the Interrupted exception).
2007-08-12 00:29:28 +00:00
Eelco Dolstra
cbfac2fdcc * Set a terminate() handler to ensure that we leave the BDB
environment cleanly even when an exception is thrown from a
  destructor.  We still crash, but we don't take all other Nix
  processes with us.
2007-05-01 15:16:17 +00:00
Eelco Dolstra
ae7990cc88 * Work around a bug in Apple's GCC preprocessor. 2007-03-30 13:24:35 +00:00
Eelco Dolstra
215505bb46 * Removed chroot support. 2007-01-13 17:54:01 +00:00
Eelco Dolstra
9dbfe242e3 * Kill a build if it has gone for more than a certain number of
seconds without producing output on stdout or stderr (NIX-65).  This
  timeout can be specified using the `--max-silent-time' option or the
  `build-max-silent-time' configuration setting.  The default is
  infinity (0).

* Fix a tricky race condition: if we kill the build user before the
  child has done its setuid() to the build user uid, then it won't be
  killed, and we'll potentially lock up in pid.wait().  So also send a
  conventional kill to the child.
2006-12-08 15:44:00 +00:00
Eelco Dolstra
a82d80ddeb * Move setuidCleanup() to libutil. 2006-12-07 16:40:41 +00:00
Eelco Dolstra
751f6d2157 * nix-setuid-helper: allow running programs under a different uid. 2006-12-06 17:29:10 +00:00
Eelco Dolstra
a9c4f66cfb * Allow unprivileged users to run the garbage collector and to do
`nix-store --delete'.  But unprivileged users are not allowed to
  ignore liveness.
* `nix-store --delete --ignore-liveness': ignore the runtime roots as
  well.
2006-12-05 02:18:46 +00:00
Eelco Dolstra
d27a73b1a9 * In addPermRoot, check that the root that we just registered can be
found by the garbage collector.  This addresses NIX-71 and is a
  particular concern in multi-user stores.
2006-12-05 00:34:42 +00:00
Eelco Dolstra
1e16d20655 * Install the worker in bindir, not libexecdir.
* Allow the worker path to be overriden through the NIX_WORKER
  environment variable.
2006-12-04 13:09:16 +00:00
Eelco Dolstra
9322b399f3 * Doh. 2006-12-03 20:41:22 +00:00
Eelco Dolstra
f4279bcde0 * Don't run setuid root when build-users is empty.
* Send startup errors to the client.
2006-12-03 16:25:19 +00:00
Eelco Dolstra
35247c4c9f * Removed `build-allow-root'.
* Added `build-users-group', the group under which builds are to be
  performed.
* Check that /nix/store has 1775 permission and is owner by the
  build-users-group.
2006-12-03 15:32:38 +00:00
Eelco Dolstra
84d6459bd5 * Use setreuid if setresuid is not available. 2006-12-03 14:32:22 +00:00
Eelco Dolstra
536595b072 * Remove most of the old setuid code.
* Much simpler setuid code for the worker in slave mode.
2006-12-02 15:45:51 +00:00
Eelco Dolstra
e2ef5e07fd * Refactoring. There is now an abstract interface class StoreAPI
containing functions that operate on the Nix store.  One
  implementation is LocalStore, which operates on the Nix store
  directly.  The next step, to enable secure multi-user Nix, is to
  create a different implementation RemoteStore that talks to a
  privileged daemon process that uses LocalStore to perform the actual
  operations.
2006-11-30 17:43:04 +00:00
Eelco Dolstra
0541ddc7e3 * Turn off synchronisation between C and C++ I/O functions. This
gives a huge speedup in operations that read or write from standard
  input/output.  (So libstdc++'s I/O isn't that bad, you just have to
  call std::ios::sync_with_stdio(false).)  For instance, `nix-store
  --register-substitutes' went from 1.4 seconds to 0.1 seconds on a
  certain input.  Another victory for Valgrind.
2006-11-18 18:56:30 +00:00
Eelco Dolstra
4ad6fb7ea3 * Fix setuid builds. 2006-09-27 21:04:07 +00:00
Eelco Dolstra
bafc1690fc * Move setuid stuff to libutil.
* Install libexpr header files.
2006-09-04 22:55:28 +00:00
Eelco Dolstra
2382a729e0 * Don't need extern "C". 2006-09-04 21:50:39 +00:00
Eelco Dolstra
75068e7d75 * Use a proper namespace.
* Optimise header file usage a bit.
* Compile the parser as C++.
2006-09-04 21:06:23 +00:00
Eelco Dolstra
547b119f25 * Support singleton values and nested lists again in `args', but print
a warning.
2006-08-29 15:40:49 +00:00
Eelco Dolstra
d19b6521fc * New configuration setting `build-max-jobs' which sets the default
for the `-j' flag (i.e., the maximum number of jobs to execute in
  parallel).  Useful on multi-processor machines.
2006-08-10 20:19:13 +00:00
Eelco Dolstra
a4273156c4 * Use $(libexecdir) to find find-runtime-roots.pl. 2006-07-20 13:21:37 +00:00
Eelco Dolstra
d51aede4af * Allow the canonical system name to be specified at runtime in the
Nix config file.
2006-07-06 15:30:37 +00:00
Eelco Dolstra
fdea084c36 * Allow `make check' to work in directories that have symlink
components.
2006-03-10 22:27:26 +00:00
Eelco Dolstra
d822bf32e4 * Close the database before the destructor runs. 2006-03-01 16:36:35 +00:00
Eelco Dolstra
5b527901ae * dirOf: return "/", not "", for paths in the root directory. Fixes NIX-26. 2006-01-09 14:52:46 +00:00
Eelco Dolstra
9311ab76a5 * Install signal handlers for SIGTERM and SIGHUP. This ensures that
Nix is properly shut down when it receives those signals.  In
  particular this ensures that killing the garbage collector doesn't
  cause a subsequent database recovery.
2005-11-04 15:34:09 +00:00
Eelco Dolstra
32282abcea * Beginning of secure multi-user Nix stores. If Nix is started as
root (or setuid root), then builds will be performed under one of
  the users listed in the `build-users' configuration variables.  This
  is to make it impossible to influence build results externally,
  allowing locally built derivations to be shared safely between
  users (see ASE-2005 paper).

  To do: only one builder should be active per build user.
2005-10-17 15:33:24 +00:00
Eelco Dolstra
a37338815d * A GC setting `gc-keep-outputs' to specify whether output paths of
derivations should be kept.
2005-02-01 22:07:48 +00:00
Eelco Dolstra
dcc37c236c * nix-store, nix-instantiate: added an option `--add-root' to
immediately add the result as a permanent GC root.  This is the only
  way to prevent a race with the garbage collector.  For instance, the
  old style

    ln -s $(nix-store -r $(nix-instantiate foo.nix)) \
      /nix/var/nix/gcroots/result

  has two time windows in which the garbage collector can interfere
  (by GC'ing the derivation and the output, respectively).  On the
  other hand,

    nix-store --add-root /nix/var/nix/gcroots/result -r \
      $(nix-instantiate --add-root /nix/var/nix/gcroots/drv \
        foo.nix)

  is safe.

* nix-build: use `--add-root' to prevent GC races.
2005-02-01 12:36:25 +00:00
Eelco Dolstra
207bdcbe86 * Automatically remove temporary root files. 2005-01-31 21:20:59 +00:00
Eelco Dolstra
22cfdfa246 * Use NIX_STORE environment variable to locate the store (in addition
to NIX_STORE_DIR) so that Nix invocations in builders in `make
  check' work correctly if the store doesn't exist.
2005-01-28 13:19:16 +00:00
Eelco Dolstra
96de272b48 * Renamed normalise.cc' -> build.cc', `storeexprs.cc' ->
`derivations.cc', etc.
* Store the SHA-256 content hash of store paths in the database after
  they have been built/added.  This is so that we can check whether
  the store has been messed with (a la `rpm --verify').
* When registering path validity, verify that the closure property
  holds.
2005-01-19 16:39:47 +00:00
Eelco Dolstra
9530cc3170 * Start move towards SHA-256 hashes instead of MD5.
* Start cleaning up unique store path generation (they weren't always
  unique; in particular the suffix ("-aterm-2.2", "-builder.sh") was
  not part of the hash, therefore changes to the suffix would cause
  multiple store objects with the same hash).
2005-01-14 13:51:38 +00:00
Eelco Dolstra
a69534fc21 * Drop ATmake / ATMatcher also in handling store expressions. 2004-10-29 11:22:49 +00:00
Eelco Dolstra
f4d44a0026 * Allow certain operations to succeed even if we don't have write
permission to the Nix store or database.  E.g., `nix-env -qa' will
  work, but `nix-env -qas' won't (the latter needs DB access).  The
  option `--readonly-mode' forces this mode; otherwise, it's only
  activated when the database cannot be opened.
2004-10-25 14:38:23 +00:00
Eelco Dolstra
dcc433de47 * Operation `--delete-generations' to delete generations of a
profile.  Arguments are either generation number, or `old' to delete
  all non-current generations.  Typical use:

  $ nix-env --delete-generations old
  $ nix-collect-garbage

* istringstream -> string2Int.
2004-09-10 13:32:08 +00:00
Eelco Dolstra
47f87072ad * A very dirty hack to make setuid installations a bit nicer to use.
Previously there was the problem that all files read by nix-env
  etc. should be reachable and readable by the Nix user.  So for
  instance building a Nix expression in your home directory meant that
  the home directory should have at least g+x or o+x permission so
  that the Nix user could reach the Nix expression.  Now we just
  switch back to the original user just prior to reading sources and
  the like.  The places where this happens are somewhat arbitrary,
  however.  Any scope that has a live SwitchToOriginalUser object in
  it is executed as the original user.

* Back out r1385.  setreuid() sets the saved uid to the new
  real/effective uid, which prevents us from switching back to the
  original uid.  setresuid() doesn't have this problem (although the
  manpage has a bug: specifying -1 for the saved uid doesn't leave it
  unchanged; an explicit value must be specified).
2004-09-09 21:12:53 +00:00