LLDB remote debug for server side Swift is failed between Linux in docker and macOS

Question

I am trying to remote debug server side swift from macOS.

lldb-server run on Ubuntu 16.04 on Docker on macOS. I am using swift-4.1-RELEASE binaries.

root@031ab2443e1a:/var/vapor# lldb-server version
lldb version 5.0.0 (git@github.com:apple/swift-lldb.git revision 76dfa56ed35eaa392f7e51088c08f08f1150d142)
  Swift-4.1 (revision f01501c324876fc07820dc28923d7088fb7af847)
  clang revision cd84be6c4294f9ec302c20c63a601cbaeaa6a017
  llvm revision cf364153438b3ac07a4a7d721159936e439ba2e7

I am also using swift-4.1-RELEASE snapshot on macOS.

[omochi@omochi-iMac-PC43 ~]$ export TOOLCHAINS=org.swift.4120180329a
[omochi@omochi-iMac-PC43 ~]$ lldb -version
lldb-360.0.0 (buildbot 2018-03-29)
  Swift-4.1 (revision f01501c324876fc07820dc28923d7088fb7af847)
  clang revision cd84be6c4294f9ec302c20c63a601cbaeaa6a017
  llvm revision cf364153438b3ac07a4a7d721159936e439ba2e7

I could connect them.

In server.

root@031ab2443e1a:/var/vapor# lldb-server platform --listen "*:31166"  --server
Connection established.

In mac.

[omochi@omochi-iMac-PC43 ~]$ lldb
(lldb) platform select remote-linux
  Platform: remote-linux
 Connected: no
(lldb) platform connect connect://127.0.0.1:31166
  Platform: remote-linux
    Triple: x86_64-*-linux-gnu
OS Version: 4.9.93 (4.9.93-linuxkit-aufs)
    Kernel: #1 SMP Wed Jun 6 16:55:56 UTC 2018
  Hostname: 031ab2443e1a
 Connected: yes
WorkingDir: /var/vapor
(lldb) platform process list
6 matching processes were found on "remote-linux"
PID    PARENT USER       TRIPLE                   NAME
====== ====== ========== ======================== ============================
1      0      (null)     x86_64-*-linux           dash
291    1                 x86_64-*-linux           vapor
423    0                 x86_64-*-linux           bash
572    291               x86_64-*-linux           Run
587    0                 x86_64-*-linux           bash
676    423               x86_64-*-linux           lldb-server

But, attach fails.

(lldb) attach 572
error: attach failed: Failed to connect port

I tested lldb in ubuntu to connect lldb-server in itself. Then attach is succeeded. So I think lldb-server run correctly to attach process.

Why attach from macOS is failed? How to solve this.

Answer 1

I found answer. lldb-server and lldb use other ports to debug. it can be specified by --min-gdbserver-port and --max-gdbserver-port options of lldb-server . And I expose these ports I specified via docker function. I finally success to connect.

Answer 2

Just to elaborate on omochimetaru answer, you can specify the ports used by LLDB-server as such:

lldb-server platform --listen "*:31166" --server --min-gdbserver-port 31200 --max-gdbserver-port 31300

And of course you need to expose those ports in your Dockerfile:

EXPOSE 31166
EXPOSE 31200-31300

And also when you run the container:

docker run --privileged --name vapor-server -p 8080:8080 -p 31166:31166 -p 31200-31300:31200-31300 vapor-image

Please note you need to run the docker as privileged ( --privileged option), otherwise attaching the debugger will fail with an Operation not Permitted error.