Segfault when indexing with SymbolServer

[rossviljoen]

Trying to index this package using SymbolServer.jl leads to a segfault (i.e. when using LanguageServer.jl).

The issue appears to lie in Base.Docs.getdoc(x::Py, @nospecialize(sig))

MWE:

julia> using SymbolServer
julia> using PythonCall
julia> env = SymbolServer.getenvtree()
julia> @time SymbolServer.symbols(env, PythonCall)

julia> versioninfo()
Julia Version 1.7.3
Commit 742b9abb4d (2022-05-06 12:58 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i5-4690 CPU @ 3.50GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, haswell)

julia> st
  ...
  [6099a3de] PythonCall v0.9.4
  [cf896787] SymbolServer v7.2.1

Full stacktrace

signal (11): Segmentation fault
in expression starting at REPL[5]:1
_Py_INCREF at /usr/local/src/conda/python-3.9.13/Include/object.h:408 [inlined]
function_code_fastcall at /usr/local/src/conda/python-3.9.13/Objects/call.c:327
PyObject_CallObject at /home/ross/prog/julia/packages/PythonCall/d8Xcl/src/cpython/pointers.jl:297 [inlined]
pycallargs at /home/ross/prog/julia/packages/PythonCall/d8Xcl/src/abstract/object.jl:210 [inlined]
#pycall#61 at /home/ross/prog/julia/packages/PythonCall/d8Xcl/src/abstract/object.jl:228
pycall at /home/ross/prog/julia/packages/PythonCall/d8Xcl/src/abstract/object.jl:218 [inlined]
#_#13 at /home/ross/prog/julia/packages/PythonCall/d8Xcl/src/Py.jl:358 [inlined]
Py at /home/ross/prog/julia/packages/PythonCall/d8Xcl/src/Py.jl:358 [inlined]
getdoc at /home/ross/prog/julia/packages/PythonCall/d8Xcl/src/Py.jl:458
_doc at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/utils.jl:194
#symbols#22 at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/symbols.jl:458
symbols##kw at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/symbols.jl:404 [inlined]
#symbols#22 at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/symbols.jl:463
symbols at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/symbols.jl:404 [inlined]
symbols at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/symbols.jl:404 [inlined]
symbols at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/symbols.jl:404 [inlined]
symbols at /home/ross/prog/julia/packages/SymbolServer/LMSFX/src/symbols.jl:404 [inlined]
top-level scope at ./timing.jl:220 [inlined]
top-level scope at ./REPL[5]:0
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:876
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:830
jl_toplevel_eval_flex at /buildworker/worker/package_linux64/build/src/toplevel.c:830
jl_toplevel_eval_in at /buildworker/worker/package_linux64/build/src/toplevel.c:944
eval at ./boot.jl:373 [inlined]
eval_user_input at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:150
repl_backend_loop at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:246
start_repl_backend at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:231
#run_repl#47 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:364
run_repl at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/REPL/src/REPL.jl:351
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
#936 at ./client.jl:394
jfptr_YY.936_35454.clone_1 at /home/ross/prog/julia/juliaup/julia-1.7.3+0.x64/lib/julia/sys.so (unknown line)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1788 [inlined]
jl_f__call_latest at /buildworker/worker/package_linux64/build/src/builtins.c:757
#invokelatest#2 at ./essentials.jl:716 [inlined]
invokelatest at ./essentials.jl:714 [inlined]
run_main_repl at ./client.jl:379
exec_options at ./client.jl:309
_start at ./client.jl:495
jfptr__start_22567.clone_1 at /home/ross/prog/julia/juliaup/julia-1.7.3+0.x64/lib/julia/sys.so (unknown line)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2247 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2429
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1788 [inlined]
true_main at /buildworker/worker/package_linux64/build/src/jlapi.c:559
jl_repl_entrypoint at /buildworker/worker/package_linux64/build/src/jlapi.c:701
main at /buildworker/worker/package_linux64/build/cli/loader_exe.c:42
unknown function (ip: 0x7f0c9822928f)
__libc_start_main at /usr/lib/libc.so.6 (unknown line)
_start at /home/ross/prog/julia/juliaup/julia-1.7.3+0.x64/bin/julia (unknown line)
Allocations: 21011684 (Pool: 21003681; Big: 8003); GC: 25

[cjdoris]

Thanks, my guess is it's segfaulting on a null python object somewhere. I can add a null check. Will take a closer look later.

[cjdoris]

My guess was correct, I could reproduce it and now it is fixed on main. Thanks for the report (and MWE)!

[rossviljoen]

thanks for the quick fix!