[lldb-dev] Using DYLD_LIBRARY_PATH and lldb

[Greg Clayton via lldb-dev]

I am surprised that this doesn't work as we make an effort to pass the current environment down to any processes that you spawn by default (at least on MacOSX we do), but the solution is easy: use the --environment variable with the "process launch" command:

(lldb) process launch --environment DYLD_LIBRARY_PATH=<mydylibpath> -- arg1 arg2 arg3

or using the short -v option:

(lldb) process launch -v DYLD_LIBRARY_PATH=<mydylibpath> -- arg1 arg2 arg3

r is an alias to "process launch --". Note that "process launch" can have arguments and the arguments you want to pass to your program might have options, so you can terminate your "process launch" arguments with "--" so that you can add your program arguments:

(lldb) process launch --environment DYLD_LIBRARY_PATH=<mydylibpath> -- --program-option=123 --environment BAR=BAZ

Note that I actually used an option "--environment BAR=BAZ" that I am passing to the program to be debugged...

It is better to use --environment because then your current LLDB or any processes that LLDB spawns won't have that environment variable set. Hope this helps.

Greg Clayton


> On Oct 23, 2015, at 1:11 AM, Haakon Sporsheim via lldb-dev <lldb-dev at lists.llvm.org> wrote:
> 
> Hi.
> 
> I'm fairly new to lldb, been using gdb most of my life.
> 
> I'm currently hacking on a small library which I'm building without
> installing. Usually I'm running tests for the library also without
> installing, but rather using DYLD_LIBRARY_PATH in this manner:
> DYLD_LIBRARY_PATH=<mydylibpath> mytestbinary
> 
> On linux using gdb when I  want to debug an issue I usually just stick
> gdb in there, which I can't do with lldb on darwin it seems:
> DYLD_LIBRARY_PATH=<mydylibpath> lldb mytestbinary
> 
> lldb gives me this result:
> (lldb) target create "<mytestbinary>"
> Current executable set to '<mytestbinary>' (x86_64).
> (lldb) r
> Process 4904 launched: '<mytestbinary>' (x86_64)
> dyld: Library not loaded: /usr/local/lib/<mydylib>
>  Referenced from: <mytestbinary>
>  Reason: image not found
> Process 4904 stopped
> * thread #1: tid = 0xfe39, 0x00007fff5fc01075 dyld`dyld_fatal_error +
> 1, stop reason = EXC_BREAKPOINT (code=EXC_I386_BPT, subcode=0x0)
>    frame #0: 0x00007fff5fc01075 dyld`dyld_fatal_error + 1
> dyld`dyld_fatal_error:
> ->  0x7fff5fc01075 <+1>: nop
> 
> dyld`dyldbootstrap::start:
>    0x7fff5fc01076 <+0>: pushq  %rbp
>    0x7fff5fc01077 <+1>: movq   %rsp, %rbp
>    0x7fff5fc0107a <+4>: pushq  %r15
> (lldb)
> 
> so it's not picking up the dylib from DYLD_LIBRARY_PATH.
> 
> I guess my question is whether this is a bug or not? Am I doing
> anything wrong, or should I not use DYLD_LIBRARY_PATH this way? Any
> suggestions and/or education would be appreciated!
> To work around this issue I've used 'install_name_tool -change old new
> <mytestbinary>' which obviously works.
> 
> Thanks, best regards
> Haakon Sporsheim
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