Remove hard-coded crayhost from Genoa switching

[Oakley Brunt (oakleybrunt)]

PR Summary

Sci/Tech Reviewer:
Code Reviewer: James Bruten (@james-bruten-mo)

This PR removes the hard-coded crayhost limitation imposed on users who were granted early-access to Gen1b (Genoa).

Warning

This PR is time-sensitive and should not be merged until just before Gen1b User Acceptance Testing begins on Monday 13th April 2026

Code Quality Checklist

• I have performed a self-review of my own code
• My code follows the project's style guidelines
• Comments have been included that aid understanding and enhance the readability of the code
• My changes generate no new warnings
• All automated checks in the CI pipeline have completed successfully

Testing

• I have tested this change locally, using the LFRic Apps rose-stem suite
• If any tests fail (rose-stem or CI) the reason is understood and acceptable (e.g. kgo changes)
• I have added tests to cover new functionality as appropriate (e.g. system tests, unit tests, etc.)
• Any new tests have been assigned an appropriate amount of compute resource and have been allocated to an appropriate testing group (i.e. the developer tests are for jobs which use a small amount of compute resource and complete in a matter of minutes)

trac.log

Test Suite Results - lfric_apps - lfric_apps/run3

Suite Information

Item	Value
Suite Name	lfric_apps/run3
Suite User	oakley.brunt
Workflow Start	2026-03-31T14:29:51
Groups Run	developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.03.2	True
jules	MetOffice/jules@2026.03.2	True
lfric_apps	oakleybrunt/LFRicApps@gen1b-uat	False
lfric_core	MetOffice/lfric_core@018e40c	True
moci	MetOffice/moci@2026.03.2	True
SimSys_Scripts	MetOffice/SimSys_Scripts@4387949	True
socrates	MetOffice/socrates@2026.03.2	True
socrates-spectral	MetOffice/socrates-spectral@2026.03.2	True
ukca	MetOffice/ukca@2026.03.2	True

Task Information

✅ succeeded tasks - 1165

Security Considerations

• I have reviewed my changes for potential security issues
• Sensitive data is properly handled (if applicable)
• Authentication and authorisation are properly implemented (if applicable)

Performance Impact

• Performance of the code has been considered and, if applicable, suitable performance measurements have been conducted

AI Assistance and Attribution

• Some of the content of this change has been produced with the assistance of Generative AI tool name (e.g., Met Office Github Copilot Enterprise, Github Copilot Personal, ChatGPT GPT-4, etc) and I have followed the Simulation Systems AI policy (including attribution labels)

Documentation

• Where appropriate I have updated documentation related to this change and confirmed that it builds correctly

PSyclone Approval

• If you have edited any PSyclone-related code (e.g. PSyKAl-lite, Kernel interface, optimisation scripts, LFRic data structure code) then please contact the TCD Team

Sci/Tech Review

• I understand this area of code and the changes being added
• The proposed changes correspond to the pull request description
• Documentation is sufficient (do documentation papers need updating)
• Sufficient testing has been completed

(Please alert the code reviewer via a tag when you have approved the SR)

Code Review

• All dependencies have been resolved
• Related Issues have been properly linked and addressed
• CLA compliance has been confirmed
• Code quality standards have been met
• Tests are adequate and have passed
• Documentation is complete and accurate
• Security considerations have been addressed
• Performance impact is acceptable

[Oakley Brunt (oakleybrunt)]

James Bruten (@james-bruten-mo) since Ed is away and this needs to be merged tomorrow evening/before Monday, would you be able to review instead and skip the Sci-Tech?

[James Bruten (james-bruten-mo)]

James Bruten (James Bruten (@james-bruten-mo)) since Ed is away and this needs to be merged tomorrow evening/before Monday, would you be able to review instead and skip the Sci-Tech?

Yeah, no problem

[James Bruten (james-bruten-mo)]

Looks good - I'll liaise with Oakley about when exactly we merge this