SQLite Forum

sqlite3BtreeHoldsMutex: Assertion error
I think you are assuming that the problem you are having is in SQLite.  And,
who knows, that could yet prove to be the case.  But historically, when problems
like this have come up, and especially problems with memory allocation, the
error has almost always been heap corruption caused by other unrelated
modules of the application that SQLite just happen to have the misfortune of
tripping over.