Different infer report between two runs with same code

[dongsushang]

Please make sure your issue is not addressed in the FAQ.

Please include the following information:

• [1.1.0 ] The version of infer from infer --version.
• [ debian-11] Your operating system and version, for example "Debian 9", "MacOS High Sierra", whether you are using Docker, etc.
• [ infer --keep-going --no-default-checkers --biabduction --starvation -j 4 --changed-files-index xxx -parameters xxx ] Which command you ran, for example infer -- make.
• [no need] The full output in a paste, for instance a gist.

I hava a java file name Example.java, there is a normal NULL_DEREFERENCE issue in Example.java. But the strange thing is that if you run the same code multiple times and run the infer check, there is only a small probability that this problem can be scanned.

[dongsushang]

we found if one thread is used to run infer，it works all right.
But it happens, when more than one thread are used.