# 11.2. Random crashes

> An app crashes when it is run. After running it 10 times in a debugger, you find it never crashes in the same place. The app is single threaded and only uses the C standard library. What programming errors could be crashing the crash, and how do you test each one?

Some part of the code overloads the memory or something, and it shows up randomly after some time.

## Solution

* The system could use a random variable that is not fixed in every execution.
* Uninitialized variable: in some languages, uninitialized variables take a random value
* Memory leak: the program runs out of memory Heap overflow, or corruption of data on the stack
* External dependencies

Close all other applications, track resource use very carefully. If there are parts of the program that can be disabled, do it. Run it on a different machine and see if the error persists.
