(Linux) machines no longer maintain the atime because it's too
expensive, and on the machines where --use-atime is useful (like the
buildfarm), reading the atimes on the entire Nix store takes way too
much time to make it practical.
UTC) rather than 0 (00:00:00). 1 is a better choice because some
programs use 0 as a special value. For instance, the Template
Toolkit uses a timestamp of 0 to denote the non-existence of a file,
so it barfs on files in the Nix store (see
template-toolkit-nix-store.patch in Nixpkgs). Similarly, Maya 2008
fails to load script directories with a timestamp of 0 and can't be
patched because it's closed source.
This will also shut up those "implausibly old time stamp" GNU tar
warnings.
(that is, call the build hook with a certain interval until it
accepts the build).
* build-remote.pl was totally broken: for all system types other than
the local system type, it would send all builds to the *first*
machine of the appropriate type.
poll for it (i.e. if we can't acquire the lock, then let the main
select() loop wait for at most a few seconds and then try again).
This improves parallelism: if two nix-store processes are both
trying to build a path at the same time, the second one shouldn't
block; it should first see if it can build other goals. Also, it
prevents the deadlocks that have been occuring in Hydra lately,
where a process waits for a lock held by another process that's
waiting for a lock held by the first.
The downside is that polling isn't really elegant, but POSIX doesn't
provide a way to wait for locks in a select() loop. The only
solution would be to spawn a thread for each lock to do a blocking
fcntl() and then signal the main thread, but that would require
pthreads.
would just silently store only (fileSize % 2^32) bytes.
* Use posix_fallocate if available when unpacking archives.
* Provide a better error message when trying to unpack something that
isn't a NAR archive.
sure that it works as expected when you pass it a derivation. That
is, we have to make sure that all build-time dependencies are built,
and that they are all in the input closure (otherwise remote builds
might fail, for example). This is ensured at instantiation time by
adding all derivations and their sources to inputDrvs and inputSrcs.
hook. This fixes a problem with log files being partially or
completely filled with 0's because another nix-store process
truncates the log file. It should also be more efficient.
the DerivationGoal runs. Otherwise, if a goal is a top-level goal,
then the lock won't be released until nix-store finishes. With
--keep-going and lots of top-level goals, it's possible to run out
of file descriptors (this happened sometimes in the build farm for
Nixpkgs). Also, for failed derivation, it won't be possible to
build it again until the lock is released.
* Idem for locks on build users: these weren't released in a timely
manner for failed top-level derivation goals. So if there were more
than (say) 10 such failed builds, you would get an error about
having run out of build users.
scan for runtime dependencies (i.e. the local machine shouldn't do a
scan that the remote machine has already done). Also pipe directly
into `nix-store --import': don't use a temporary file.
(e.g. an SSH connection problem) and permanent failures (i.e. the
builder failed). This matters to Hydra (it wants to know whether it
makes sense to retry a build).
