Individual tests were never successfully removing 'foo.db' (the error was ignored), which caused everything but the first test to fail on my vmhgfs filesystem. Adding the relevant defer db.Close() and rows.Close() calls fixed the leaks, enabling os.Remove() to work.
Original:
--- FAIL: TestInsert (0.00 seconds)
sqlite3_test.go:42: Failed to create table:%!(EXTRA *errors.errorString=unable to open database file)
With corrections:
--- FAIL: TestInsert (0.00 seconds)
sqlite3_test.go:42: Failed to create table: unable to open database file