tests: set RUST_BACKTRACE=1 in e2e tests
This should be very useful when tests fail because of a panic.
@@ -46,6 +46,7 @@ impl TestEnvironment {
cmd.current_dir(current_dir);
cmd.args(args);
cmd.env_clear();
+ cmd.env("RUST_BACKTRACE", "1");
cmd.env("HOME", self.home_dir.to_str().unwrap());
let timestamp = chrono::DateTime::parse_from_rfc3339("2001-02-03T04:05:06+07:00").unwrap();
let mut command_number = self.command_number.borrow_mut();
