makemigrations --check no longer prints the changes

[David Sanders]

As a result of #34051 the --check flag on makemigrations simply exits 1 without writing any changes.

This makes sense as it's consistent with other uses of --check.

However one consequence of this change is that my CI server no longer prints the changes it thinks I need to make – and this makes the situations where the local dev & CI are different, harder to debug.

I'd like to propose reverting this change and instead forcing --dry-run to be set if --check is supplied. This way makemigrations goes through the motions of what it needs to write, outputting those changes to the log but the dry flag prevents any migrations from being written.

[David Sanders]

PR: ​https://github.com/django/django/pull/16723

[Mariusz Felisiak]

Thanks for the ticket, however I don't think it's worth the inconsistency. You could re-run makemigrations when makemigrations --check exists with 1, e.g.

RESULT=`makemigrations --check`
if [ "$RESULT" -gt 0 ]; then
    makemigrations --dry-run
fi;
exit $RESULT

[Jacob Walls]

Or instead of a bash script, use something like if: failure() in your CI pipeline. Forcing --dry-run to once again be provided when --check is provided goes against the original motivation for the change: it's unintuitive (to me) that for --check you would need to guard against files being written your tree and therefore even know about the --dry-run option.

[David Sanders]

Forcing --dry-run to once again be provided when --check is provided goes against the original motivation for the change

By forcing I mean makemigrations does the forcing… see the PR for what I mean ;)

(I thought this was made clear by "This way makemigrations goes through the motions of what it needs to write, outputting those changes to the log but the dry flag prevents any migrations from being written.")

[Jacob Walls]

Accepting based on ​forum discussion.

[Adam Johnson]

Marking as a release blocker because I consider it a regression, as discussed on the forum.

[Jacob Walls]

​new PR

[Natalia <124304+nessita@…>]

In f7389c4:

Fixed #34457 -- Restored output for makemigrations --check.

Co-authored-by: David Sanders <shang.xiao.sanders@…>
Co-authored-by: Natalia <124304+nessita@…>

[Natalia <124304+nessita@…>]

In 8eba6ef:

[5.0.x] Fixed #34457 -- Restored output for makemigrations --check.

Co-authored-by: David Sanders <shang.xiao.sanders@…>
Co-authored-by: Natalia <124304+nessita@…>

Backport of f7389c4b07ceeb036436e065898e411b247bca78 from main

[Natalia <124304+nessita@…>]

In 90c3d71d:

[4.2.x] Fixed #34457 -- Restored output for makemigrations --check.

Co-authored-by: David Sanders <shang.xiao.sanders@…>
Co-authored-by: Natalia <124304+nessita@…>

Backport of f7389c4b07ceeb036436e065898e411b247bca78 from main