<html>#2742: Change Seed_Magnetic_Fields scheduling so it can be used by more thorns
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<tr><td style='text-align:right'> Reporter:</td><td>Samuel Cupp</td></tr>
<tr><td style='text-align:right'> Status:</td><td>new</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td>ET_2023_11</td></tr>
<tr><td style='text-align:right'> Version:</td><td></td></tr>
<tr><td style='text-align:right'> Type:</td><td>enhancement</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>major</td></tr>
<tr><td style='text-align:right'>Component:</td><td>EinsteinToolkit thorn</td></tr>
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<p>Comment (by Roland Haas):</p>
<p>Hello Sam, what official docs we have on this is here:</p>
<p><a data-is-external-link="true" href="https://docs.einsteintoolkit.org/et-docs/Policies_to_retire_functionality" rel="nofollow">https://docs.einsteintoolkit.org/et-docs/Policies_to_retire_functionality</a></p>
<p>So more or less what you describe.</p>
<p>Expect this to still catch people by surprise though. There is an (inofficial since I don't think we ever really discussed keeping it) list of deprecated and retired functionality that I try to keep here: <a data-is-external-link="true" href="https://docs.einsteintoolkit.org/et-docs/Deprecated_features" rel="nofollow">https://docs.einsteintoolkit.org/et-docs/Deprecated_features</a> (but the last entry is from 2020 so it is almost certainly not up to date).</p>
<p>No warning in the thorn to be deprecated is needed. Other codes do that, increasing levels of annoyance as the deprecation date, which is a fixed date recorded in the code, comes closer, up to and including refusing to <em>run</em> if the compiled functionality is too old. In the ET the warning comes in the form of a list of deprecated features in the release announcements and discussion in the ET calls.</p>
<p>Previous advise wrt to breaking changes is eg here: </p>
<p>Note that you cannot deprecate (change) default parameter <em>values</em>, since that would lead to silent changes in behaviour. This is not foolproof of course, just look at the trouble we have with <code>GRHydro::sources_spatial_order</code> and <code>ADMMacros::spatial_order</code>. Or at least it must have been a very very long time that anyone has ever relied on that default.</p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2742/change-seed_magnetic_fields-scheduling-so'>https://bitbucket.org/einsteintoolkit/tickets/issues/2742/change-seed_magnetic_fields-scheduling-so</a></p>
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