通过向测试二进制文件传递附加参数，可以获得一个测试二进制文件来过滤它运行的测试；Cargo也直接expose 了这一点.因此，cargo test test_extract_failure将只运行该特定 case .(如果您有其他测试出现panic ，并且预计会失败，这样他们就不会调用我将要提到的rust_panic函数，只留下令人不快的调用，这是很方便的.)
为了使用gdb，您需要直接运行测试二进制文件(如果您使用Cargo，它会在子进程中运行，因此gdb不会在其中陷入panic ).Cargo会告诉你文件名target/gunzip-c62d8688496249d8.您可以直接使用--test来运行它，使其成为测试运行:
$ target/gunzip-c62d8688496249d8 --test test_extract_failure
running 1 test
test test_extract_failure ... FAILED
failures:
---- test_extract_failure stdout ----
task 'test_extract_failure' panicked at 'assertion failed: result.is_err()', /home/dhardy/other/flate2-rs/tests/gunzip.rs:19
failures:
test_extract_failure
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured
task '<main>' panicked at 'Some tests failed', /home/rustbuild/src/rust-buildbot/slave/nightly-linux/build/src/libtest/lib.rs:250
现在把它和gdb联系起来.有一个方便的函数，可以插入断点rust_panic.一旦进入gdb，break rust_panic意味着每当有什么东西触发panic 时，它就会暂停，然后再进行真正的放松.
以下是一次会议的最终结果:
$ gdb target/demo-92d91e26f6ebc557
…
Reading symbols from target/demo-92d91e26f6ebc557...done.
(gdb) break rust_panic
Breakpoint 1 at 0xccb60
(gdb) run --test test_extract_failure
Starting program: /tmp/demo/target/demo-92d91e26f6ebc557 --test test_extract_failure
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
running 1 test
[New Thread 0x7ffff6ef4700 (LWP 14254)]
[New Thread 0x7ffff5fff700 (LWP 14255)]
[Switching to Thread 0x7ffff5fff700 (LWP 14255)]
Breakpoint 1, 0x0000555555620b60 in rust_panic ()
(gdb) bt
#0 0x0000555555620b60 in rust_panic ()
#1 0x0000555555621274 in unwind::begin_unwind_inner::hb821324209c8ed246Qc ()
#2 0x000055555556bb6d in unwind::begin_unwind::h7834652822578025936 ()
#3 0x000055555556b9fd in demo::do_something () at <std macros>:8
#4 0x000055555556b98e in demo::test_extract_failure () at src/lib.rs:3
#5 0x000055555559aa4b in task::TaskBuilder::try_future::closure.8077 ()
#6 0x000055555560fd03 in task::TaskBuilder::spawn_internal::closure.30919 ()
#7 0x000055555561f672 in task::Task::spawn::closure.5759 ()
#8 0x0000555555621cac in rust_try_inner ()
#9 0x0000555555621c96 in rust_try ()
#10 0x000055555561f713 in unwind::try::ha8078a6ae9b50ccepFc ()
#11 0x000055555561f51c in task::Task::run::hdb5fabf381084abafOb ()
#12 0x000055555561f168 in task::Task::spawn::closure.5735 ()
#13 0x0000555555620595 in thread::thread_start::h4d73784c295273b3i6b ()
#14 0x00007ffff79c2314 in start_thread () from /usr/lib/libpthread.so.0
#15 0x00007ffff72e25bd in clone () from /usr/lib/libc.so.6
(gdb)
在这种特殊情况下，#0#2和#5#15是噪声，#3和#4是我们想要的信号.