I've added a .mailmap to my repository containing one line:

User Name <user.name@mail.domain>

As soon as this commit is pushed to stash it will crash Git on the Stash server:

com.atlassian.stash.exception.ServerException: An error occurred while executing an external process: 'C:\Program Files (x86)\Git\cmd\git.exe rev-list --format=%H%x02%h%x02%P%x02%p%x02%aN%x02%aE%x02%at%n%B%n%x03 --ignore-missing --stdin --' exited with code -1073741819
at com.atlassian.stash.internal.scm.git.GitCommandExitHandler.evaluateThrowable(GitCommandExitHandler.java:120) ~[na:na]
at com.atlassian.stash.internal.scm.git.GitCommandExitHandler.onError(GitCommandExitHandler.java:163) ~[na:na]
at com.atlassian.stash.scm.DefaultCommandExitHandler.onExit(DefaultCommandExitHandler.java:35) ~[stash-spi-2.5.0.jar:na]
at com.atlassian.stash.scm.BaseCommand.callExitHandler(BaseCommand.java:141) ~[stash-spi-2.5.0.jar:na]
at com.atlassian.stash.scm.BaseCommand$CommandFuture.internalGet(BaseCommand.java:257) ~[stash-spi-2.5.0.jar:na]
at com.atlassian.stash.scm.BaseCommand$CommandFuture.get(BaseCommand.java:238) ~[stash-spi-2.5.0.jar:na]
at ...

We are using Stash on Windows. This will also crash Git when listing the commits or basically every time you navigate in the repository