> # Normal case
> print(err)
<error/rlang_error>
foo
Backtrace:
  1. rlang::catch_cnd(f())
  8. rlang:::f()
  9. rlang:::g()
 10. rlang:::h()

> # From `last_error()`
> print(last_error())
<error/rlang_error>
foo
Backtrace:
  1. rlang::catch_cnd(f())
  8. rlang:::f()
  9. rlang:::g()
 10. rlang:::h()
Run `rlang::last_trace()` to see the full context.

> # Saved from `last_error()`
> saved <- last_error()
> print(saved)
<error/rlang_error>
foo
Backtrace:
  1. rlang::catch_cnd(f())
  8. rlang:::f()
  9. rlang:::g()
 10. rlang:::h()
Run `rlang::last_trace()` to see the full context.

> # Saved from `last_error()`, but no longer last
> last_error_env$cnd <- error_cnd("foo")
> print(saved)
<error/rlang_error>
foo
Backtrace:
  1. rlang::catch_cnd(f())
  8. rlang:::f()
  9. rlang:::g()
 10. rlang:::h()

