# Crash when using \`@info\` during type conversion

**URL:** <https://discourse.julialang.org/t/crash-when-using-info-during-type-conversion/23354>\
**Category:** General Usage\
**Created:** [April 20, 2019, 5:53pm UTC](https://discourse.julialang.org/t/crash-when-using-info-during-type-conversion/23354 "2019-04-20T17:53:00Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![tk3369](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tk3369/32/2824_2.png) [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Post date:** [April 20, 2019, 5:53pm UTC](https://discourse.julialang.org/t/crash-when-using-info-during-type-conversion/23354/1 "2019-04-20T17:53:00Z")

</div>

MWE:

```julia
julia> abstract type S end

julia> struct S1 <: S end

julia> struct S2 <: S end

julia> s1 = S1()
S1()

julia> @info(s1)
[ Info: S1()

julia> Base.convert(S2, x::S1) = begin @info(x); S2(); end

julia> struct Foo
         s::S2
       end

julia> Foo(s1)
Unreachable reached at 0x116d2ecc7

signal (4): Illegal instruction: 4
in expression starting at no file:0
print at ./strings/io.jl:31
print_to_string at ./strings/io.jl:123
string at ./strings/io.jl:156
#handle_message#2 at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/Logging/src/ConsoleLogger.jl:108
unknown function (ip: 0x116d2ec2c)
jl_fptr_trampoline at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1864
handle_message at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/Logging/src/ConsoleLogger.jl:100
convert at ./logging.jl:320
jl_fptr_trampoline at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1864
Type at ./REPL[8]:2
jl_fptr_trampoline at /Users/osx/buildbot/slave/package_osx64/build/src/gf.c:1864
do_call at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:323
eval_stmt_value at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:362 [inlined]
eval_body at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:759
jl_interpret_toplevel_thunk_callback at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:885
unknown function (ip: 0xfffffffffffffffe)
unknown function (ip: 0x11302491f)
unknown function (ip: 0xffffffffffffffff)
jl_interpret_toplevel_thunk at /Users/osx/buildbot/slave/package_osx64/build/src/interpreter.c:894
jl_toplevel_eval_flex at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:764
jl_toplevel_eval at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:773 [inlined]
jl_toplevel_eval_in at /Users/osx/buildbot/slave/package_osx64/build/src/toplevel.c:793
eval at ./boot.jl:328
eval_user_input at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:85
macro expansion at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/REPL/src/REPL.jl:117 [inlined]
#26 at ./task.jl:259
jl_apply at /Users/osx/buildbot/slave/package_osx64/build/src/./julia.h:1571 [inlined]
start_task at /Users/osx/buildbot/slave/package_osx64/build/src/task.c:572
Allocations: 4645830 (Pool: 4645095; Big: 735); GC: 9
Illegal instruction: 4

```

My config:

```julia
julia> versioninfo()
Julia Version 1.1.0
Commit 80516ca202 (2019-01-21 21:24 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin14.5.0)
  CPU: Intel(R) Core(TM) i5-4258U CPU @ 2.40GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, haswell)
Environment:
  JULIA_NUM_THREADS = 4

```

---

<div class="post-metadata">

**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [April 20, 2019, 6:22pm UTC](https://discourse.julialang.org/t/crash-when-using-info-during-type-conversion/23354/2 "2019-04-20T18:22:19Z")

</div>

[https://github.com/JuliaLang/julia/issues/31649](https://github.com/JuliaLang/julia/issues/31649)

Shoud have been `Base.convert(::Type{S2}, x::S1)`

---

<div class="post-metadata">

**Author:** ![tk3369](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tk3369/32/2824_2.png) [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Post date:** [April 20, 2019, 6:26pm UTC](https://discourse.julialang.org/t/crash-when-using-info-during-type-conversion/23354/3 "2019-04-20T18:26:39Z")

</div>

Silly me 😅  
But, the conversion worked fine without the `@info` call.