macOS下lldb直接附加进程失败，手动启动debugserver可正常连接

问题现象 #

执行lldb -p <PID>或在lldb会话中运行process attach -p <PID>时，始终报错：

error: Connection shut down by remote side while waiting for reply to initial handshake packet

相关日志如下：

❯ /Applications/Xcode.app/Contents/Developer/usr/bin/lldb  -O log 
(lldb) process attach -p 16986
 <   1> send packet: +
 history[1] tid=0x0103 <   1> send packet: +
 <  19> send packet: $QStartNoAckMode#b0
error: attach failed: Connection shut down by remote side while waiting for reply to initial handshake packet

正常工作的场景 #

手动启动debugserver后，再将lldb连接到该服务，一切运行正常：

启动debugserver #

❯ /Library/Developer/CommandLineTools/Library/PrivateFrameworks/LLDB.framework/Versions/A/Resources/debugserver localhost:1234 --attach=17154 
debugserver-@(#)PROGRAM:LLDB  PROJECT:lldb-1500.0.404.7
 for arm64.
Attaching to process 17154...
Listening to port 1234 for a connection from localhost...
Waiting for debugger instructions for process 17154.

连接lldb #

❯ /Applications/Xcode.app/Contents/Developer/usr/bin/lldb                                                          
(lldb) process connect connect://localhost:1234
Process 17154 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
    frame #0: 0x000000018ec6c3e8 libsystem_kernel.dylib`__semwait_signal + 8
libsystem_kernel.dylib`:
->  0x18ec6c3e8 <+8>:  b.lo   0x18ec6c408               ; <+40>
    0x18ec6c3ec <+12>: pacibsp 
    0x18ec6c3f0 <+16>: stp    x29, x30, [sp, #-0x10]!
    0x18ec6c3f4 <+20>: mov    x29, sp
Target 0: (lldb_test_program) stopped.
(lldb) 

测试程序信息 #

测试程序无签名或保护机制，代码如下：

#include <stdio.h>
#include <unistd.h>
#include <signal.h>

void signal_handler(int sig) {
    printf("Received signal %d, but continuing...\n", sig);
}

int main() {
    signal(SIGINT, signal_handler);
    
    printf("Test program started, PID: %d\n", getpid());
    printf("This program will run indefinitely.\n");
    printf("You can attach lldb to PID: %d\n", getpid());
    printf("Press Ctrl+C to see signal handling, or kill the process to exit.\n");
    
    int counter = 0;
    while(1) {
        printf("Counter: %d\n", counter++);
        sleep(2);  
        
        if(counter % 10 == 0) {
            printf("Reminder: PID is %d\n", getpid());
        }
    }
    
    return 0;
}

编译命令：gcc -g -o lldb_test_program lldb_test_program.c

疑问 #

理论上lldb -p <pid>应该和手动启动debugserver再连接的效果一致，但实际存在差异。请问这种差异是什么原因导致的？是预期行为还是我的系统配置有误？如需更多上下文或系统信息，可补充提供。

内容的提问来源于stack exchange，提问作者John Joker