panic: runtime error: invalid memory address or nil pointer dereference [recovered]panic: runtime error: invalid memory address or nil pointer dereference [recovered] panic: runtime error: invalid memory address or nil pointer dereference[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x15524f5] goroutine 5730 [running]:testing.tRunner.func1(0xc000178100) /usr/local/Cellar/go/1.12.5/libexec/src/testing/testing.go:830 +0x392panic(0x16211e0, 0x1c42e30) /usr/local/Cellar/go/1.12.5/libexec/src/runtime/panic.go:522 +0x1b5go.mongodb.org/mongo-driver/mongo.executeTestRunnerOperation(0xc000178100, 0xc0009ff0a0, 0xc000bf7a20, 0x7, 0xc0003a83e8, 0x1, 0xc000ee3da0) /Users/manny.eppinger/go/src/go.mongodb.org/mongo-driver/mongo/transactions_test.go:620 +0x555go.mongodb.org/mongo-driver/mongo.runTransactionsTestCase.func1(0xc000178100) /Users/manny.eppinger/go/src/go.mongodb.org/mongo-driver/mongo/transactions_test.go:311 +0xe52testing.tRunner(0xc000178100, 0xc000ebe180) /usr/local/Cellar/go/1.12.5/libexec/src/testing/testing.go:865 +0xc0created by testing.(*T).Run /usr/local/Cellar/go/1.12.5/libexec/src/testing/testing.go:916 +0x35aexit status 2