Some files have been moved around inside CDT's source tree

[jonahgraham]

As part of the migration of the Eclipse Terminal from the CDT project, which should be complete for the 2025-12 release, some terminal projects have moved to Eclipse Platform, and others have been relocated within the CDT source tree to better reflect their use going forward.

This means that when you update to latest main branch you may have some project in Eclipse that are now closed or seem to be missing their .project file. Remove those projects from your workspace to continue your work.
Please see https://github.com/eclipse-cdt/cdt/issues?q=label%3Aterminal%20milestone%3A12.3.0 for all the PRs that are affecting the structure.

[jonahgraham]

An example of an error you may see is documented here #1337 (comment)