Less nesting, where that improves readability. More nesteing, where
that improves readability, but most importantly:
Expose individual functions separately so that they can be more easily
built directly, eg.:
`nix build --impure --expr '(import ./testing-python.nix {system = builtins.currentSystem;}).mkTestDriver'`
At nixpkgs root:
`rg redirectSerial ./` does not result in any other match
nor does
`rg USE_SERIAL ./` except for an unrelated match in:
pkgs/tools/graphics/argyllcms/default.nix
Bash's standard behavior of not propagating non-zero exit codes
through a pipeline is unexpected and almost universally
unwanted. Default to setting `pipefail` for the command being run;
it can still be turned off by prefixing the pipeline with
`set +o pipefail` if needed.
Also, set `errexit` and `nonunset` options to make the first command
of consecutive commands separated by `;` fail, and disallow
dereferencing unset variables respectively.
When importing Nixpkgs within Nixpkgs, we should not consider aliases
to ensure we don't rely on them internally.
There are probably more places that need to be converted.
The root filesystem resizing step, `resize2fs -M', does not provide any
control over the amount of slack left in the result. It can produce an
arbitrarily tight fit, depending on how well the payload aligns with
ext4 data structures.
This is problematic, as NixOS must create a few files and directories
during its first boot, before the root is enlarged to match the size of
the containing SD card.
An overly tight fit can cause failures in the first stage:
mkdir: can't create directory '/mnt-root/proc': No space left on device
or in the second stage:
install: cannot create directory '/var': No space left on device
A previous version of `make-ext4-fs' (before PR #79368) was explicitly
"reserving" 16 MiB of free space in the final filesystem. Manually
calculating the size of an ext4 filesystem is a perilous endeavor,
however, and the method it employed was apparently unreliable.
Reverting is consequently not a good option.
A solution would be to create some sort of "balloon" occupying inodes
and blocks in the image prior to invoking `resize2fs -M', and to remove
these temporary files/directories before the compression step.
This changeset takes the simpler approach of simply dropping the
resizing step.
Note that this does *not* result in a larger image in general, as the
current procedure does not truncate the `.img' file anyway. In fact, it
has been observed to yield *smaller* compressed images---probably
because of some "noise" left after resizing. E.g., before-vs-after:
-r--r--r-- 2 root root 607M 1. Jan 1970 nixos-sd-image-21.11pre-git-x86_64-linux.img.zst
-r--r--r-- 2 root root 606M 1. Jan 1970 nixos-sd-image-21.11pre-git-x86_64-linux.img.zst
For now you had to know that the actions are retried for 900s when
seeing an error like
> Traceback (most recent call last):
> File "/nix/store/dbvmxk60sv87xsxm7kwzzjm7a4fhgy6y-nixos-test-driver/bin/.nixos-test-driver-wrapped", line 927, in run_tests
> exec(tests, globals())
> File "<string>", line 1, in <module>
> File "<string>", line 31, in <module>
> File "/nix/store/dbvmxk60sv87xsxm7kwzzjm7a4fhgy6y-nixos-test-driver/bin/.nixos-test-driver-wrapped", line 565, in wait_for_file
> retry(check_file)
> File "/nix/store/dbvmxk60sv87xsxm7kwzzjm7a4fhgy6y-nixos-test-driver/bin/.nixos-test-driver-wrapped", line 142, in retry
> raise Exception("action timed out")
> Exception: action timed out
in your (hydra) build failure. Due to the absence of timestamps you were
left guessing if the machine was just slow, someone passed a low timeout
value (which they couldn't until now) or whatever might have happened.
By making this error a bit more descriptive (by including the elapsed
time) these hopefully become more useful.
Our test driver exposes a bunch of variables and functions, which
pyflakes doesn't recognise by default because it assumes that the test
script is executed standalone. In reality however the test driver script
is using exec() on the testScript.
Fortunately pyflakes has $PYFLAKES_BUILTINS, which are the attributes
that are globally available on all modules to be checked. Since we only
have one module, using this environment variable is fine as opposed to
my first approach to this, which tried to use the unstable internal API
of pyflakes.
The attributes are gathered by the main derivation of the test driver,
because we don't want to end up defining a new attribute in the test
driver module just to being confused why using it in a test will result
in an error.
Another way we could have gathered these attributes would be in
mkDriver, which is where the linting takes place. However, we do have a
different set of Python dependencies in scope and duplicating these will
again just cause confusion over having it at one location only.
Signed-off-by: aszlig <aszlig@nix.build>
Co-Authored-By: aszlig <aszlig@nix.build>
So far, we have used "black" for formatting the test code, which is
rather strict and opinionated and when used inline in Nix expressions it
creates all sorts of trouble.
One of the main annoyances is that when using strings coming from Nix
expressions (eg. store paths or option definitions from NixOS modules),
completely unrelated changes could cause tests to fail, since eg. black
wants lines to be broken.
Another downside of enforcing a certain kind of formatting is that it
makes the Nix expression code inconsistent because we're mixing two
spaces of indentation (common in nixpkgs) with four spaces of
indentation as defined in PEP-8. While this is perfectly fine for
standalone Python files, it really looks ugly and inconsistent IMO when
used within Nix strings.
What we actually want though is a linter that catches problems early on
before actually running the test, because this is *actually* helping in
development because running the actual VM test takes much longer.
This is the reason why I switched from black to pyflakes, because the
latter actually has useful checks, eg. usage of undefined variables,
invalid format arguments, duplicate arguments, shadowed loop vars and
more.
Signed-off-by: aszlig <aszlig@nix.build>
Closes: https://github.com/NixOS/nixpkgs/issues/72964
On my system I have XWayland disabled and therefore only WAYLAND_DISPLAY
is set. This ensures that the graphical output will still be enabled on
such setups (both Wayland and X11 are supported by the viewer).
Work around missing /dev files inside runInLinuxVM by creating a
symlink before calling nixos-enter.
This fixes https://github.com/NixOS/nixpkgs/issues/93381.
I ran into this issue when trying to create a VMware image that boots from EFI.
Thanks @colemickens for reporting this and @danielfullmer for fixing the same thing in in qemu-vm.nix (37676e77cb) and explaining what the issue was.
This ensures the following gptfdisk warning won't happen:
```
Warning: File size is not a multiple of 512 bytes! Misbehavior is likely!
```
Additionally, helps towards aligning the partition to be more optimal
for the underlying storage.
It is actually impossible to align for the actual underlying storage
optimally because we don't know what the block device will be!
But aligning on 1MiB should help.
This is a bit of a thorny issue. See, the actual `diskSize` variable is
for the *total* disk size, not for the filesystem!
The automatic numbers are meant to compute the *filesystem* required
space. So we have to add any other reserved space!
We have different requirements for reserved space. E.g. there could be
none (when it's actually a filesystem image). There could also be 1MiB
for alignment for an MBR image, legacy+gpt needs 2MiB, then GPT with an
ESP ("bootSize") needs to take the boot partition and GPT size into
account too!
Though luckily(?) for this latter situation we can cheat! As noted in the
change, `bootSize` is NOT the boot partition size. It is actually the
offset where the target filesystem starts.
Reserved space includes:
- inodes space in use (2 blocks per)
- about 5.2% of the space
The 5.2% reserved space was computed empirically when working on a
previous EXT4 image builder. It seems to stabilize around 5% even for
much larger filesystems.
On some filesystems, `du` without `--apparent-size` will not give the
actual size for a file. Using `--apparent-size` will give us the actual
file size.
Though, this is not actually correct still. 1000 × 1 bytes is not 1000
bytes. It is 1000 × ceil(filesize/blockSize)*blockSize.
So instead of adding up the actual file sizes. We are adding up the
block sizes.
Note that this also changes the builder to work with *bytes*, rather
than with any other units. Doing maths on bytes is less likely to go
awry than doing it on other units.
When performing OCR, some of the Tesseract settings perform better than
others on a variety of different workloads, but they mostly take
~negligible incremental time to run compared to the overhead of running
the ImageMagick filters.
After this commit, we try using all three of the current Tesseract
models (classic, LSTM, and classic+LSTM) to generate output text. This
fixes chromium-90's tests at release-20.09, and should make cases where
you're looking for *specific* text better, with the tradeoff of running
Tesseract multiple times.
To make it sensible to cherrypick this into release-20.09, this doesn't
change the existing API surface for the test driver. In particular,
get_screen_text continues to have the existing behaviour.
Make the revision metadata constant, in order to avoid needless retesting.
The human version (e.g. 21.05-pre) is left as is, because it is useful
for external modules that test with e.g. nixosTest and rely on that
version number.
the nix store may contain hardlinks: derivations may output them
directly, or users may be using store optimization which automatically
hardlinks identical files in the nix store.
The presence of these links are intended to be a 'transparent'
optimization. However, when creating a squashfs image, the image
will be different depending on whether hard links were present
on the filesystem, leading to reproducibility problems.
By passing '-no-hardlinks' to mksquashfs the files are stored
as duplicates in the squashfs image. Since squashfs has support
for duplicate files this does not lead to a larger image.
For more details see
https://github.com/NixOS/nixpkgs/issues/114331
The hydra tarball step would fail due to the nodes attribute not being
properly inherited. Since we can't execute all the tests and release
steps locally anymore (thanks to the JSONification and faster hydra
eval) these errors will probably keep in appearing.
This is hopefully the last of those introduced by me test runner
refactoring.
Error was seen on hydra (https://hydra.nixos.org/build/129282411):
> unpacking sources
> unpacking source archive /nix/store/bp95x52h6nv3j8apxrryyj2rviw682k1-source
> source root is source
> patching sources
> autoconfPhase
> No bootstrap, bootstrap.sh, configure.in or configure.ac. Assuming this is not an GNU Autotools package.
> configuring
> release name is nixpkgs-21.03pre249116.1088f059401
> git-revision is 1088f05940
> building
> no Makefile, doing nothing
> running tests
> warning: you did not specify '--add-root'; the result might be removed by the garbage collector
> warning: you did not specify '--add-root'; the result might be removed by the garbage collector
> checking Nixpkgs on i686-linux
> checking Nixpkgs on x86_64-linux
> checking Nixpkgs on x86_64-darwin
> checking eval-release.nix
> trace: `mkStrict' is obsolete; use `mkOverride 0' instead.
> trace: `lib.nixpkgsVersion` is deprecated, use `lib.version` instead!
> trace: warning: lib.readPathsFromFile is deprecated, use a list instead
> trace: Warning: `showVal` is deprecated and will be removed in the next release, please use `traceSeqN`
> trace: lib.zip is deprecated, use lib.zipAttrsWith instead
> checking find-tarballs.nix
> trace: `mkStrict' is obsolete; use `mkOverride 0' instead.
> trace: `lib.nixpkgsVersion` is deprecated, use `lib.version` instead!
> trace: warning: lib.readPathsFromFile is deprecated, use a list instead
> trace: Warning: `showVal` is deprecated and will be removed in the next release, please use `traceSeqN`
> trace: lib.zip is deprecated, use lib.zipAttrsWith instead
> error: while evaluating anonymous function at /build/source/maintainers/scripts/find-tarballs.nix:6:1, called from undefined position:
> while evaluating 'operator' at /build/source/maintainers/scripts/find-tarballs.nix:27:16, called from undefined position:
> while evaluating 'immediateDependenciesOf' at /build/source/maintainers/scripts/find-tarballs.nix:39:29, called from /build/source/maintainers/scripts/find-tarballs.nix:27:44:
> while evaluating anonymous function at /build/source/lib/attrsets.nix:234:10, called from undefined position:
> while evaluating anonymous function at /build/source/maintainers/scripts/find-tarballs.nix:40:37, called from /build/source/lib/attrsets.nix:234:16:
> while evaluating 'derivationsIn' at /build/source/maintainers/scripts/find-tarballs.nix:42:19, called from /build/source/maintainers/scripts/find-tarballs.nix:40:40:
> while evaluating 'canEval' at /build/source/maintainers/scripts/find-tarballs.nix:48:13, called from /build/source/maintainers/scripts/find-tarballs.nix:43:9:
> while evaluating the attribute 'nodes' at /build/source/nixos/lib/testing-python.nix:195:23:
> attribute 'nodes' missing, at /build/source/nixos/lib/testing-python.nix:193:16
> build time elapsed: 0m0.122s 0m0.043s 17m51.526s 0m56.668s
> builder for '/nix/store/96rk3c74vrk6m3snm7n6jhis3j640pn4-nixpkgs-tarball-21.03pre249116.1088f059401.drv' failed with exit code 1
In 5500dc8 we introduced the --keep-vm-state flag and defaulted to that
flag not being set. This lead to the `runInMachine` tests not longer
working and that going unnoticed for quite some time now.
