New comment by tornaria on void-packages repository

https://github.com/void-linux/void-packages/pull/47888#issuecomment-1869011818

Comment:
> We need to ignore `checkdepends` during non-testing-build

This only affects order, in the sense that `sort-dependencies` will not add anything, just sort.

For example:
```
$ ./xbps-src sort-dependencies python3-pytest-cov
python3-pytest-cov
```
even if `python3-pytest-cov` checkdepends on `python3-process-tests`.

OTOH,in
```
$ ./xbps-src sort-dependencies python3-process-tests python3-pytest-cov
python3-pytest-cov
python3-process-tests
```
it is irrelevant for non-testing-build in which order these two packages are built, so it should not be a problem.

The only case where this would make a difference is if there is a build-check cycle. Then this will print a warning, and IMO it should be considered a bug.

Example:
```
$ XBPS_CHECK_PKGS=full ./xbps-src sort-dependencies python3-jupyter_server python3-jupyter_server_terminals
tsort: /tmp/tmp.owWM5auH2j: input contains a loop:
tsort: python3-jupyter_server
tsort: python3-jupyter_server_terminals
python3-jupyter_server_terminals
python3-jupyter_server
```
Note this is only a cycle because of `XBPS_CHECK_PKGS=full` which is one way build-check cycles can be broken. Indeed:
```
$ XBPS_CHECK_PKGS=yes ./xbps-src sort-dependencies python3-jupyter_server python3-jupyter_server_terminals
python3-jupyter_server_terminals
python3-jupyter_server
```