Sqlite’s source code is public domain. Surely if you dropped the sqlite source code into Linux, it wouldn’t suddenly become GPL code? I’m not sure how it works
The Linux kernel would become a GPLv2-licensed derivative work of SQLite, but that doesn’t matter, because public domain works, by definition, are not subject to copyright restrictions.
Claiming copyright on an unmodified public domain work is a lie, so in some circumstances could be an element of fraud, but still wouldn’t be a copyright violation.
