Transition and toolchain freeze (https://release.debian.org/testing/freeze_policy.html#transition https://release.debian.org/testing/freeze_policy.html#transi..

Transition and toolchain freeze (https://release.debian.org/testing/freeze_policy.html#transition https://release.debian.org/testing/freeze_policy.html#transi...), where certain critical packages (https://release.debian.org/testing/essential-and-build-essential.txt https://release.debian.org/testing/essential-and-build-essen...) are frozen and updates are discouraged (not blocked) unless that the update would be too onerous to bugtest.