add MCF migration support

[tomkralidis]

As discussed at FOSS4G Europe 2026, this PR adds the ability to migrate MCFs (currently supporting 1.0 -> 2.0) via CLI or library mode.

[pvgenuchten]

What about adding as a optional parameter on export: “migrate first if needed”

Also, what happens if one calls migrate on a record which is already migrated?

[tomkralidis]

What about adding as a optional parameter on export: “migrate first if needed”

Not sure. May be cleaner to keep concerns / workflows separate in that regard?

[pvgenuchten]

migrate_from_1_0, consider to add from-version and to-version in method name, so when migrating from 2.1 to 2.3 can involve 2 migrations.
First 2.1-2.2, then 2.2-2.3

[pvgenuchten]

Not sure. May be cleaner to keep concerns / workflows separate in that regard?

Problem is that record export will fail if record is not migrated, maybe fail on export, indicating to migrate record first?

[tomkralidis]

Not sure. May be cleaner to keep concerns / workflows separate in that regard?

Problem is that record export will fail if record is not migrated, maybe fail on export, indicating to migrate record first?

Export indeed fails:

$ pygeometa metadata generate old-1.0.mcf.yml --schema oarec-record
...
pygeometa.core.MCFReadError: invalid / unsupported version 1.0

What about updating the exception message to something like pygeometa.core.MCFReadError: invalid / unsupported version 1.0; please migrate to the latest MCF version ?

[pvgenuchten]

yes, let's go for that

what happens if mcf has no version, do we assume latest? if fails without version, use message: parsing failed, your record does not have a version set, try setting the version and migrating to latest