julia - 如何打印一个错误的完整堆栈跟踪？

Question

println不打印堆栈跟踪，此代码

try
  eval(Meta.parse("invalidfn()"))
catch error
  println(error)
end

产生

UndefVarError(:invalidfn)

并且 error.msg或 fieldnames(error)不起作用。

Answer 1

您可以将 catch_backtrace 与 @error standard library中的Logging宏一起使用:

julia> try
         eval(Meta.parse("invalidfn()"))
       catch e
         @error "Something went wrong" exception=(e, catch_backtrace())
       end
┌ Error: Something went wrong
│   exception =
│    UndefVarError: invalidfn not defined
│    Stacktrace:
│     [1] top-level scope at REPL[1]:1
│     [2] eval at ./boot.jl:330 [inlined]
│     [3] eval(::Expr) at ./client.jl:425
│     [4] top-level scope at REPL[1]:2
│     [5] eval(::Module, ::Any) at ./boot.jl:330
│     [6] eval_user_input(::Any, ::REPL.REPLBackend) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.3/REPL/src/REPL.jl:86
│     [7] macro expansion at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.3/REPL/src/REPL.jl:118 [inlined]
│     [8] (::REPL.var"#26#27"{REPL.REPLBackend})() at ./task.jl:333
└ @ Main REPL[1]:4

或者，您可以直接调用(未记录)三参数 showerror :

julia> try
         eval(Meta.parse("invalidfn()"))
       catch e
         showerror(stdout, e, catch_backtrace())
       end
UndefVarError: invalidfn not defined
Stacktrace:
 [1] top-level scope at REPL[1]:1
 [2] eval at ./boot.jl:330 [inlined]
 [3] eval(::Expr) at ./client.jl:425
 [4] top-level scope at REPL[1]:2
 [5] eval(::Module, ::Any) at ./boot.jl:330
 [6] eval_user_input(::Any, ::REPL.REPLBackend) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.3/REPL/src/REPL.jl:86
 [7] macro expansion at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.3/REPL/src/REPL.jl:118 [inlined]
 [8] (::REPL.var"#26#27"{REPL.REPLBackend})() at ./task.jl:333