Test cases should not modify the host system

[Stebalien]

Currently, some of the test cases modify the git config (e.g. finds_author_git in tests/test_cargo_new.rs). This is not nice 😢.

[alexcrichton]

It's a bug that this test is modifying global configuration, the reset of $HOME should in theory tell git where it should be modifying this. Does git read some other environment variables to figure out where the global configuration should go?

[Stebalien]

It uses XDG_CONFIG_HOME. The test suite should also set GIT_CONFIG_NOSYSTEM.

According to the manual

GIT_CONFIG_NOSYSTEM
Whether to skip reading settings from the system-wide $(prefix)/etc/gitconfig file. This environment variable can be used along with $HOME and $XDG_CONFIG_HOME to create a predictable environment for a picky script, or you can set it temporarily to avoid using a buggy /etc/gitconfig file while waiting for someone with sufficient permissions to fix it.

[alexcrichton]

Whelp

[Stebalien]

Thanks!