lldb-mi hangs on MacOS

[busjaeger]

When I run lldb-mi on MacOS it hangs. Here is the console output:

(gdb)
-file-exec-and-symbols "test"
^done
(gdb)
=library-loaded,id="[...]/test",target-name="[...]/test",host-name="[...]/test",symbols-loaded="0",loaded_addr="-",size="23838720"
r test
~"Process 34501 launched: '[...]/test' (x86_64)\n"
^done
(gdb)
=thread-created,id="1",group-id="i1"
=thread-selected,id="1"
(gdb)
=library-unloaded,id="[...]/test",target-name="[...]/test",host-name="[...]/test"
(gdb)
=library-loaded,id="/usr/lib/dyld",target-name="/usr/lib/dyld",host-name="/usr/lib/dyld",symbols-loaded="0",loaded_addr="0x0000000101eb4000",size="442368"
=library-loaded,id="[...]/test",target-name="[...]/test",host-name="[...]/test",symbols-loaded="0",loaded_addr="0x0000000100000000",size="23838720"
*running,thread-id="all"
(gdb)

Here is a sample of the process obtained via Activity Monitor: https://gist.github.com/busjaeger/c5653cd197fb0c82d9ca79bf95f521f0

If I enter r again, and answer n to killing the running process, the process executes and completes successfully.

r
There is a running process, kill it and restart?: [Y/n] n
^done
(gdb)
(gdb)
=library-loaded,id="[...]/compression/zstd/lib/libzstd.1.3.4.dylib",target-name="[...]/compression/zstd/lib/libzstd.1.3.4.dylib",host-name="[...]/compression/zstd/lib/libzstd.1.3.4.dylib",symbols-loaded="1",symbols-path="[...]/compression/zstd/lib/libzstd.1.3.4.dylib.dSYM/Contents/Resources/DWARF/libzstd.1.3.4.dylib",loaded_addr="0x0000000102154000",size="720896"
=library-loaded,id="/usr/lib/libz.1.dylib",target-name="/usr/lib/libz.1.dylib",host-name="/usr/lib/libz.1.dylib",symbols-loaded="0",loaded_addr="0x00007ff8261d9000",size="77824"
=library-loaded,id="/usr/lib/libSystem.B.dylib",target-name="/usr/lib/libSystem.B.dylib",host-name="/usr/lib/libSystem.B.dylib",symbols-loaded="0",loaded_addr="0x00007ff8262b9000",size="8192"
=library-loaded,id="/usr/lib/system/libcache.dylib",target-name="/usr/lib/system/libcache.dylib",host-name="/usr/lib/system/libcache.dylib",symbols-loaded="0",loaded_addr="0x00007ff8262b4000",size="20480"
=library-loaded,id="/usr/lib/system/libcommonCrypto.dylib",target-name="/usr/lib/system/libcommonCrypto.dylib",host-name="/usr/lib/system/libcommonCrypto.dylib",symbols-loaded="0",loaded_addr="0x00007ff826270000",size="49152"
=library-loaded,id="/usr/lib/system/libcompiler_rt.dylib",target-name="/usr/lib/system/libcompiler_rt.dylib",host-name="/usr/lib/system/libcompiler_rt.dylib",symbols-loaded="0",loaded_addr="0x00007ff826299000",size="32768"
=library-loaded,id="/usr/lib/system/libcopyfile.dylib",target-name="/usr/lib/system/libcopyfile.dylib",host-name="/usr/lib/system/libcopyfile.dylib",symbols-loaded="0",loaded_addr="0x00007ff82628f000",size="40960"
=library-loaded,id="/usr/lib/system/libcorecrypto.dylib",target-name="/usr/lib/system/libcorecrypto.dylib",host-name="/usr/lib/system/libcorecrypto.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b264000",size="598016"
=library-loaded,id="/usr/lib/system/libdispatch.dylib",target-name="/usr/lib/system/libdispatch.dylib",host-name="/usr/lib/system/libdispatch.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b322000",size="290816"
=library-loaded,id="/usr/lib/system/libdyld.dylib",target-name="/usr/lib/system/libdyld.dylib",host-name="/usr/lib/system/libdyld.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b4e6000",size="49152"
=library-loaded,id="/usr/lib/system/libkeymgr.dylib",target-name="/usr/lib/system/libkeymgr.dylib",host-name="/usr/lib/system/libkeymgr.dylib",symbols-loaded="0",loaded_addr="0x00007ff8262ab000",size="4096"
=library-loaded,id="/usr/lib/system/libmacho.dylib",target-name="/usr/lib/system/libmacho.dylib",host-name="/usr/lib/system/libmacho.dylib",symbols-loaded="0",loaded_addr="0x00007ff82624e000",size="24576"
=library-loaded,id="/usr/lib/system/libquarantine.dylib",target-name="/usr/lib/system/libquarantine.dylib",host-name="/usr/lib/system/libquarantine.dylib",symbols-loaded="0",loaded_addr="0x00007ff8258cd000",size="12288"
=library-loaded,id="/usr/lib/system/libremovefile.dylib",target-name="/usr/lib/system/libremovefile.dylib",host-name="/usr/lib/system/libremovefile.dylib",symbols-loaded="0",loaded_addr="0x00007ff8262a9000",size="8192"
=library-loaded,id="/usr/lib/system/libsystem_asl.dylib",target-name="/usr/lib/system/libsystem_asl.dylib",host-name="/usr/lib/system/libsystem_asl.dylib",symbols-loaded="0",loaded_addr="0x00007ff820460000",size="94208"
=library-loaded,id="/usr/lib/system/libsystem_blocks.dylib",target-name="/usr/lib/system/libsystem_blocks.dylib",host-name="/usr/lib/system/libsystem_blocks.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b20d000",size="8192"
=library-loaded,id="/usr/lib/system/libsystem_c.dylib",target-name="/usr/lib/system/libsystem_c.dylib",host-name="/usr/lib/system/libsystem_c.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b3aa000",size="561152"
=library-loaded,id="/usr/lib/system/libsystem_collections.dylib",target-name="/usr/lib/system/libsystem_collections.dylib",host-name="/usr/lib/system/libsystem_collections.dylib",symbols-loaded="0",loaded_addr="0x00007ff8262a1000",size="20480"
=library-loaded,id="/usr/lib/system/libsystem_configuration.dylib",target-name="/usr/lib/system/libsystem_configuration.dylib",host-name="/usr/lib/system/libsystem_configuration.dylib",symbols-loaded="0",loaded_addr="0x00007ff824b7a000",size="16384"
=library-loaded,id="/usr/lib/system/libsystem_containermanager.dylib",target-name="/usr/lib/system/libsystem_containermanager.dylib",host-name="/usr/lib/system/libsystem_containermanager.dylib",symbols-loaded="0",loaded_addr="0x00007ff823e26000",size="118784"
=library-loaded,id="/usr/lib/system/libsystem_coreservices.dylib",target-name="/usr/lib/system/libsystem_coreservices.dylib",host-name="/usr/lib/system/libsystem_coreservices.dylib",symbols-loaded="0",loaded_addr="0x00007ff825f87000",size="20480"
=library-loaded,id="/usr/lib/system/libsystem_darwin.dylib",target-name="/usr/lib/system/libsystem_darwin.dylib",host-name="/usr/lib/system/libsystem_darwin.dylib",symbols-loaded="0",loaded_addr="0x00007ff81db09000",size="40960"
=library-loaded,id="/usr/lib/system/libsystem_dnssd.dylib",target-name="/usr/lib/system/libsystem_dnssd.dylib",host-name="/usr/lib/system/libsystem_dnssd.dylib",symbols-loaded="0",loaded_addr="0x00007ff8262ac000",size="32768"
=library-loaded,id="/usr/lib/system/libsystem_featureflags.dylib",target-name="/usr/lib/system/libsystem_featureflags.dylib",host-name="/usr/lib/system/libsystem_featureflags.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b3a7000",size="12288"
=library-loaded,id="/usr/lib/system/libsystem_info.dylib",target-name="/usr/lib/system/libsystem_info.dylib",host-name="/usr/lib/system/libsystem_info.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b4fc000",size="176128"
=library-loaded,id="/usr/lib/system/libsystem_m.dylib",target-name="/usr/lib/system/libsystem_m.dylib",host-name="/usr/lib/system/libsystem_m.dylib",symbols-loaded="0",loaded_addr="0x00007ff8261ec000",size="397312"
=library-loaded,id="/usr/lib/system/libsystem_malloc.dylib",target-name="/usr/lib/system/libsystem_malloc.dylib",host-name="/usr/lib/system/libsystem_malloc.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b2f6000",size="180224"
=library-loaded,id="/usr/lib/system/libsystem_networkextension.dylib",target-name="/usr/lib/system/libsystem_networkextension.dylib",host-name="/usr/lib/system/libsystem_networkextension.dylib",symbols-loaded="0",loaded_addr="0x00007ff8203fb000",size="94208"
=library-loaded,id="/usr/lib/system/libsystem_notify.dylib",target-name="/usr/lib/system/libsystem_notify.dylib",host-name="/usr/lib/system/libsystem_notify.dylib",symbols-loaded="0",loaded_addr="0x00007ff81df2f000",size="61440"
=library-loaded,id="/usr/lib/system/libsystem_product_info_filter.dylib",target-name="/usr/lib/system/libsystem_product_info_filter.dylib",host-name="/usr/lib/system/libsystem_product_info_filter.dylib",symbols-loaded="1",symbols-path="",loaded_addr="0x00007ff82c517000",size="4096"
=library-loaded,id="/usr/lib/system/libsystem_sandbox.dylib",target-name="/usr/lib/system/libsystem_sandbox.dylib",host-name="/usr/lib/system/libsystem_sandbox.dylib",symbols-loaded="0",loaded_addr="0x00007ff824b7e000",size="24576"
=library-loaded,id="/usr/lib/system/libsystem_secinit.dylib",target-name="/usr/lib/system/libsystem_secinit.dylib",host-name="/usr/lib/system/libsystem_secinit.dylib",symbols-loaded="0",loaded_addr="0x00007ff8262a6000",size="12288"
=library-loaded,id="/usr/lib/system/libsystem_kernel.dylib",target-name="/usr/lib/system/libsystem_kernel.dylib",host-name="/usr/lib/system/libsystem_kernel.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b4a2000",size="229376"
=library-loaded,id="/usr/lib/system/libsystem_platform.dylib",target-name="/usr/lib/system/libsystem_platform.dylib",host-name="/usr/lib/system/libsystem_platform.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b4f2000",size="40960"
=library-loaded,id="/usr/lib/system/libsystem_pthread.dylib",target-name="/usr/lib/system/libsystem_pthread.dylib",host-name="/usr/lib/system/libsystem_pthread.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b4da000",size="49152"
=library-loaded,id="/usr/lib/system/libsystem_symptoms.dylib",target-name="/usr/lib/system/libsystem_symptoms.dylib",host-name="/usr/lib/system/libsystem_symptoms.dylib",symbols-loaded="0",loaded_addr="0x00007ff821ca8000",size="32768"
=library-loaded,id="/usr/lib/system/libsystem_trace.dylib",target-name="/usr/lib/system/libsystem_trace.dylib",host-name="/usr/lib/system/libsystem_trace.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b24b000",size="102400"
=library-loaded,id="/usr/lib/system/libunwind.dylib",target-name="/usr/lib/system/libunwind.dylib",host-name="/usr/lib/system/libunwind.dylib",symbols-loaded="0",loaded_addr="0x00007ff82627c000",size="45056"
=library-loaded,id="/usr/lib/system/libxpc.dylib",target-name="/usr/lib/system/libxpc.dylib",host-name="/usr/lib/system/libxpc.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b20f000",size="245760"
=library-loaded,id="/usr/lib/libc++abi.dylib",target-name="/usr/lib/libc++abi.dylib",host-name="/usr/lib/libc++abi.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b48c000",size="90112"
=library-loaded,id="/usr/lib/libobjc.A.dylib",target-name="/usr/lib/libobjc.A.dylib",host-name="/usr/lib/libobjc.A.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b369000",size="253952"
=library-loaded,id="/usr/lib/liboah.dylib",target-name="/usr/lib/liboah.dylib",host-name="/usr/lib/liboah.dylib",symbols-loaded="0",loaded_addr="0x00007ff826287000",size="32768"
=library-loaded,id="/usr/lib/libc++.1.dylib",target-name="/usr/lib/libc++.1.dylib",host-name="/usr/lib/libc++.1.dylib",symbols-loaded="0",loaded_addr="0x00007ff81b433000",size="364544"
[...]
(gdb)
=thread-exited,id="1",group-id="i1"
=thread-group-exited,id="i1",exit-code="0"
*stopped,reason="exited-normally"
(gdb)

The debugger in Eclipse and VSCode also hang for this executable (I believe due to the same problem). I don't have this problem with simple 'Hello World' executables. I suspect the reason is that this executable loads some dynamic libraries. The stack trace seems to suggest the process is blocked initializing python.

Please let me know if you need more info. Thanks in advance for any pointers!

[busjaeger]

FYI, I built lldb-mi from source against llvm installed with brew:

brew install llvm
brewllvm=$(ls -d /usr/local/Cellar/llvm/*)
cd ~/Projects
git clone https://github.com/lldb-tools/lldb-mi
cd lldb-mi
cmake -DCMAKE_PREFIX_PATH=$brewllvm .
cmake --build .

Not sure if this is related, but when I follow the steps in Verifying Python Support, I get:

✗ export PYTHONPATH=`/usr/local/Cellar/llvm/13.0.1_1/bin/lldb -P`
✗ python3 -c 'import lldb'
[1]    64445 segmentation fault  python3 -c 'import lldb'

I don't get that seg fault with:

✗ export PYTHONPATH=`/Library/Developer/CommandLineTools/usr/bin/lldb -P`
✗ python3 -c 'import lldb'

Is there some way to build lldb-mi against lldb that comes with XCode?

[busjaeger]

Looks like this is somehow related to the debug information for libzstd. When I remove the directory libzstd.1.3.4.dylib.dSYM, the debugger no longer hangs.