This should be a non-empty set, and so we don't want people doing this
by accident. We remove the zero-0 constructor with a little inheritance
trickery.
`DerivedPath::Built` and `DerivationGoal` were previously using a
regular set with the convention that the empty set means all outputs.
But it is easy to forget about this rule when processing those sets.
Using `OutputSpec` forces us to get it right.
This basically reverts 6e5165b773.
It fixes errors like
sandbox-exec: <internal init prelude>:292:47: unable to open sandbox-minimal.sb: not found
when trying to run a development Nix installed in a user's home
directory.
Also, we're trying to minimize the number of installed files
to make it possible to deploy Nix as a single statically-linked
binary.
This makes 'nix develop' set the Linux personality in the same way
that the actual build does, allowing a command like 'nix develop
nix#devShells.i686-linux.default' on x86_64-linux to work correctly.
These only functioned if a very narrow combination of conditions held:
- The result path does not yet exist (--check did not result in
repeated builds), AND
- The result path is not available from any configured substituters, AND
- No remote builders that can build the path are available.
If any of these do not hold, a derivation would be built 0 or 1 times
regardless of the repeat option. Thus, remove it to avoid confusion.
We shouldn't skip this if the supplementary group list is empty,
because then the sandbox won't drop the supplementary groups of the
parent (like "root").
The new experimental feature 'cgroups' enables the use of cgroups for
all builds. This allows better containment and enables setting
resource limits and getting some build stats.
It occurred when a output of the dependency was already available,
so it didn't need rebuilding and didn't get added to the
inputDrvOutputs.
This process-related info wasn't suitable for the purpose of finding
the actual input paths for the builder. It is better to do this in
absolute terms by querying the store.
Cgroups are now only used for derivations that require the uid-range
range feature. This allows auto UID allocation even on systems that
don't have cgroups (like macOS).
Also, make things work on modern systems that use cgroups v2 (where
there is a single hierarchy and no "systemd" controller).
Call it as `['nix', '__build-remote', ... ]` rather than the previous
`["__build-remote", "nix __build-remote", ... ]` which seemed to have
been most likely unintended
After we've send "\2\n" to the parent, we can't send a serialized
exception anymore. It will show up garbled like
$ nix-build --store /tmp/nix --expr 'derivation { name = "foo"; system = "x86_64-linux"; builder = "/foo/bar"; }'
this derivation will be built:
/nix/store/xmdip0z5x1zqpp6gnxld3vqng7zbpapp-foo.drv
building '/nix/store/xmdip0z5x1zqpp6gnxld3vqng7zbpapp-foo.drv'...
ErrorErrorEexecuting '/foo/bar': No such file or directory
error: builder for '/nix/store/xmdip0z5x1zqpp6gnxld3vqng7zbpapp-foo.drv' failed with exit code 1
readDerivation is pretty slow, and while it may not be significant for
some use cases, on things like ghc-nix where we have thousands of
derivations is really slows things down.
So, this just doesn’t do the impure derivation check if the impure
derivation experimental feature is disabled. Perhaps we could cache
the result of isPure() and keep the check, but this is a quick fix to
for the slowdown introduced with impure derivations features in 2.8.0.
