Cannot step in .so library source code loaded with dlopen, breakpoints do not work.

[BlackZork]

OS: Arch Linux, updated 15.01.2026
VSCode version: code-oss 1.107.1 (from package)
CodeLLDB version: 1.12.1
Compiler: gcc version 15.2.1 20260103 (GCC)
cmake: 4.2.1

[zork@archdevel lldb_so_problem]$ uname -a
Linux archdevel 6.18.5-arch1-1 #1 SMP PREEMPT_DYNAMIC Sun, 11 Jan 2026 17:10:53 +0000 x86_64 GNU/Linux

I cannot step in .so library source code loaded with dlopen, breakpoints do not work.

It works with gdb extensions (tested webfreak.debug, M$ C++ is not usable in OSS version).

I've attached minimal project that reproduces my issue. I am using CMake tools 1.21.36 to build and run it.

Adding a breakpoint in main.cpp works ok:

codelldb         0x0000556048fc6d88 Broadcaster("lldb.target")::BroadcastEvent (event_sp = 0x55604a0cba98 Event: broadcaster = 0x556049b443d0 (lldb.target), type = 0x00000001 (breakpoint-changed), data = {bkpt: 3 type: breakpoint added}, unique=false) hijack = 0x0000000000000000
codelldb         Target::AddBreakpoint (internal = no) => break_id = 3: file = '/home/zork/sources/lldb_so_problem/modmqttd/main.cpp', line = 18, exact_match = 0

codelldb         GDBRemoteCommunicationClient::SendGDBStoppointTypePacket() add at addr = 0x555555557f38
codelldb         0x0000556048fc6d88 Broadcaster("lldb.target")::BroadcastEvent (event_sp = 0x556049c36f38 Event: broadcaster = 0x556049b443d0 (lldb.target), type = 0x00000001 (breakpoint-changed), data = {bkpt: 3 type: locations resolved}, unique=false) hijack = 0x0000000000000000
codelldb         Added location (skipped prologue: no): 3.1:
  module = /home/zork/sources/lldb_so_problem/build/modmqttd/modmqttd
  compile unit = main.cpp
  function = std::shared_ptr<ConverterPlugin> dll_import<ConverterPlugin>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>, char const*)
  mangled function = _Z10dll_importI15ConverterPluginESt10shared_ptrIT_ENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEPKc
  location = /home/zork/sources/lldb_so_problem/modmqttd/main.cpp:18:26
  address = 0x0000555555557f38
  resolved = true
  hardware = false
  hit count = 0

Adding a breakpoint in bits.hpp:

codelldb         0x0000556048fc6d88 Broadcaster("lldb.target")::BroadcastEvent (event_sp = 0x556049d9d028 Event: broadcaster = 0x556049b443d0 (lldb.target), type = 0x00000001 (breakpoint-changed), data = {bkpt: 4 type: breakpoint added}, unique=false) hijack = 0x0000000000000000
codelldb         Target::AddBreakpoint (internal = no) => break_id = 4: file = '/home/zork/sources/lldb_so_problem/stdconv/bits.hpp', line = 8, exact_match = 0

codelldb         0x0000556048fc6d88 Broadcaster("lldb.target")::BroadcastEvent (event_sp = 0x55604a13c6e8 Event: broadcaster = 0x556049b443d0 (lldb.target), type = 0x00000001 (breakpoint-changed), data = {bkpt: 5 type: breakpoint added}, unique=false) hijack = 0x0000000000000000
codelldb         Target::AddBreakpoint (internal = no) => break_id = 5: file = 'bits.hpp', line = 8, exact_match = 0

codelldb         Target::RemoveBreakpointByID (break_id = 5, internal = no)

codelldb         Target::DisableBreakpointByID (break_id = 5, internal = no)

codelldb         0x0000556048fc6d88 Broadcaster("lldb.target")::BroadcastEvent (event_sp = 0x556049c36f38 Event: broadcaster = 0x556049b443d0 (lldb.target), type = 0x00000001 (breakpoint-changed), data = {bkpt: 5 type: breakpoint disabled}, unique=false) hijack = 0x0000000000000000
codelldb         0x0000556048fc6d88 Broadcaster("lldb.target")::BroadcastEvent (event_sp = 0x55604a0cba98 Event: broadcaster = 0x556049b443d0 (lldb.target), type = 0x00000001 (breakpoint-changed), data = {bkpt: 5 type: breakpoint removed}, unique=false) hijack = 0x0000000000000000

When I step into DataConverter::getArgs from main Codelldb shows me assembly. No idea why it cannot see source files, paths in stdconv.so are absolute:

[zork@archdevel stdconv]$ objdump -C -l -d ./stdconv.so |grep hpp
/home/zork/sources/lldb_so_problem/stdconv/plugin.hpp:13
/home/zork/sources/lldb_so_problem/libmodmqttconv/converter.hpp:5
/home/zork/sources/lldb_so_problem/libmodmqttconv/converter.hpp:6
/home/zork/sources/lldb_so_problem/libmodmqttconv/converter.hpp:7
[...]

I am out of ideas what could be wrong and I appreciate any help with this issue.

lldb_so_problem.tar.gz

[BlackZork]

Module stdconv.so is not added to "Modules" list and debug_info list does not list stdconv.so module in debug console.

Output from log enable lldb dyld:

intern-state     DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit called for pid 21588
intern-state     DYLDRendezvous::Resolve address size: 8, padding 4
intern-state     DYLDRendezvous::Resolve cursor = 0x7ffff7ffdb58
intern-state     m_previous Rendezvous: version = 1, map_addr = 0x00007ffff7ffe2f0, brk = 0x00007ffff7fc57c0, state = 0 (eConsistent), ldbase = 0x00007ffff7fc2000
intern-state     m_current  Rendezvous: version = 1, map_addr = 0x00007ffff7ffe2f0, brk = 0x00007ffff7fc57c0, state = 1 (eAdd), ldbase = 0x00007ffff7fc2000
intern-state     bool DYLDRendezvous::UpdateSOEntriesFromRemote() action = eNoAction
intern-state     bool DYLDRendezvous::UpdateSOEntries() action = eNoAction
intern-state     DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit pid 21588 stop_when_images_change=false
intern-state     DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit called for pid 21588
intern-state     DYLDRendezvous::Resolve address size: 8, padding 4
intern-state     DYLDRendezvous::Resolve cursor = 0x7ffff7ffdb58
intern-state     m_previous Rendezvous: version = 1, map_addr = 0x00007ffff7ffe2f0, brk = 0x00007ffff7fc57c0, state = 1 (eAdd), ldbase = 0x00007ffff7fc2000
intern-state     m_current  Rendezvous: version = 1, map_addr = 0x00007ffff7ffe2f0, brk = 0x00007ffff7fc57c0, state = 0 (eConsistent), ldbase = 0x00007ffff7fc2000
intern-state     bool DYLDRendezvous::UpdateSOEntriesFromRemote() action = eAddModules
intern-state     DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit pid 21588 stop_when_images_change=false

shared-library-event is getting hit. Before dlopen:

Current breakpoints:
Kind: shared-library-event
-1: names = {'_dl_debug_state', 'rtld_db_dlactivity', '__dl_rtld_db_dlactivity', 'r_debug_state', '_r_debug_state', '_rtld_debug_state'}, language = c, module = ld-linux-x86-64.so.2, locations = 1, resolved = 1, hit count = 2

  -1.1: where = ld-linux-x86-64.so.2`_dl_debug_state, address = 0x00007ffff7fc57c0, resolved, hit count = 2 

after dlopen:

Current breakpoints:
Kind: shared-library-event
-1: names = {'_dl_debug_state', 'rtld_db_dlactivity', '__dl_rtld_db_dlactivity', 'r_debug_state', '_r_debug_state', '_rtld_debug_state'}, language = c, module = ld-linux-x86-64.so.2, locations = 1, resolved = 1, hit count = 4

  -1.1: where = ld-linux-x86-64.so.2`_dl_debug_state, address = 0x00007ffff7fc57c0, resolved, hit count = 4```