Commit graph

8 commits

Author SHA1 Message Date
John Ericson
c11836126b Harden tests' bash
Use `set -u` and `set -o pipefail` to catch accidental mistakes and
failures more strongly.

 - `set -u` catches the use of undefined variables
 - `set -o pipefail` catches failures (like `set -e`) earlier in the
   pipeline.

This makes the tests a bit more robust. It is nice to read code not
worrying about these spurious success paths (via uncaught) errors
undermining the tests. Indeed, I caught some bugs doing this.

There are a few tests where we run a command that should fail, and then
search its output to make sure the failure message is one that we
expect. Before, since the `grep` was the last command in the pipeline
the exit code of those failing programs was silently ignored. Now with
`set -o pipefail` it won't be, and we have to do something so the
expected failure doesn't accidentally fail the test.

To do that we use `expect` and a new `expectStderr` to check for the
exact failing exit code. See the comments on each for why.

`grep -q` is replaced with `grepQuiet`, see the comments on that
function for why.

`grep -v` when we just want the exit code is replaced with `grepInverse,
see the comments on that function for why.

`grep -q -v` together is, surprise surprise, replaced with
`grepQuietInverse`, which is both combined.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-03-08 10:26:30 -05:00
Eelco Dolstra
0687e16c4a Fix a crash in DerivedPath::Built::toJSON() with impure derivations
The use of 'nullptr' here didn't result in a null JSON value, but in a
nullptr being cast to a string, which aborts.
2022-12-15 16:02:27 +01:00
Artturin
8e7bbc3c35 tests/impure-derivations.sh: remove unknown experimental feature 'ca-references'
ca-references was stabilized in d589a6aa8a
2022-11-03 21:53:11 +02:00
Eelco Dolstra
6377442c98 tests/impure-derivations.sh: Ensure that inputAddressed build fails 2022-03-31 17:38:15 +02:00
Eelco Dolstra
162beb2595 Fix test 2022-03-31 13:43:20 +02:00
Eelco Dolstra
b2ae922747 tests/impure-derivations.sh: Restart daemon 2022-03-31 13:43:20 +02:00
Eelco Dolstra
18935e8b9f Support fixed-output derivations depending on impure derivations 2022-03-31 13:43:20 +02:00
Eelco Dolstra
5cd72598fe Add support for impure derivations
Impure derivations are derivations that can produce a different result
every time they're built. Example:

  stdenv.mkDerivation {
    name = "impure";
    __impure = true; # marks this derivation as impure
    outputHashAlgo = "sha256";
    outputHashMode = "recursive";
    buildCommand = "date > $out";
  };

Some important characteristics:

* This requires the 'impure-derivations' experimental feature.

* Impure derivations are not "cached". Thus, running "nix-build" on
  the example above multiple times will cause a rebuild every time.

* They are implemented similar to CA derivations, i.e. the output is
  moved to a content-addressed path in the store. The difference is
  that we don't register a realisation in the Nix database.

* Pure derivations are not allowed to depend on impure derivations. In
  the future fixed-output derivations will be allowed to depend on
  impure derivations, thus forming an "impurity barrier" in the
  dependency graph.

* When sandboxing is enabled, impure derivations can access the
  network in the same way as fixed-output derivations. In relaxed
  sandboxing mode, they can access the local filesystem.
2022-03-31 13:43:20 +02:00