error: Execution was interrupted, reason: EXC_BAD_ACCESS (code=1, address=0x18).

Reference

EXC_BAD_ACCESS crash error: Understanding and solving it

Thread Sanitizer explained: Data Races in Swift

Symptom

error: Execution was interrupted, reason: EXC_BAD_ACCESS (code=1, address=0x18).

The process has been returned to the state before expression evaluation.

Investigation

In Xcode, Menu >> Product >> Scheme >> Edit Scheme

From Run >> Diagnostics >> Check Runtime Sanitization

Solution

In my case, accessed timer.userInfo which timer has been already invalidated. It was due to multiple async timer invocations. Inserted timer.isValid check just before accessing timer.userInfo.