This change updates the instructions for building a NixOS ISO so that it's clear how to do it.
Previously, the instructions stated to set NIXOS_CONFIG prior to running `nix-build`, yet the example provided by-passed NIXOS_CONFIG anyway. But the *really* important missing piece is the need for nixos/default.nix. See #21840.
This change removes the NIXOS_CONFIG verbiage, and adds steps to clone nixpkgs and (most importantly) cd'ing into nixpkgs/nixos. That way, the reader may think: *Oh, so I need a default.nix and a configuration.nix. Ahhh, OK.*
I purposely added the redundant default.nix argument.
This is based on a prototype Nicolas B. Pierron worked on during a
discussion we had at FOSDEM.
A new version with a workaround for problems of the reverted original.
Discussion: https://github.com/NixOS/nixpkgs/commit/3f2566689
* manual: Mark commands that require root
Mark every command that requires to be run as root by prefixing them
with '#' instead of '$'.
* manual: Add note about commands that require root
This command was useful when NixOS was spread across multiple
repositories, but now it's pretty pointless (and obfuscates what
happens, i.e. "git clone git://github.com/NixOS/nixpkgs.git").
- Enforce that an option declaration has a "defaultText" if and only if the
type of the option derives from "package", "packageSet" or "nixpkgsConfig"
and if a "default" attribute is defined.
- Enforce that the value of the "example" attribute is wrapped with "literalExample"
if the type of the option derives from "package", "packageSet" or "nixpkgsConfig".
- Warn if a "defaultText" is defined in an option declaration if the type of
the option does not derive from "package", "packageSet" or "nixpkgsConfig".
- Warn if no "type" is defined in an option declaration.
For example, this allows writing
nix.package = /nix/store/786mlvhd17xvcp2r4jmmay6jj4wj6b7f-nix-1.10pre4206_896428c;
Also, document types.package in the manual.
By default this is now enabled, and it has to be explicitely enabled
using "enableOCR = true". If it is set to false, any usage of
getScreenText or waitForText will fail with an error suggesting to pass
enableOCR.
This should get rid of the rather large dependency on tesseract which
we don't need for most tests.
Note, that I'm using system("type -P") here to check whether tesseract
is in PATH. I know it's a bashism but we already have other bashisms
within the test scripts and we also run it with bash, so IMHO it's not a
problem here.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
As promised in the previous commit, this can be used similarly to
$machine->waitForWindow, where you supply a regular expression and it's
retrying OCR until the regexp matches.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Basically, this creates a screenshot and throws tesseract at it to
recognize the characters from the screenshot. In order to produce a
result that is well enough, we're using lanczos scaling and scale the
image up to 400% of its original size.
This provides the base functionality for a new Machine method which will
be called waitForText. I originally had that idea long ago when writing
the VM tests for VirtualBox and Chromium, but thought it would be
disproportionate to the case.
The downside however is that VM tests now depend on tesseract, but given
the average runtime of our tests it really shouldn't have a too big
impact and it's only a runtime dependency after all.
Another issue is that the OCR process takes quite some time to finish,
but IMHO it's better (as in more deterministic) than to rely on sleep().
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
