ssh tests fail when test/test.jl and test/libgit2.jl run on same worker

[tkelman]

cc @Keno, this might be related to the trouble in #17651 (comment)
on ubuntu 14.04:

julia> Base.runtests("test libgit2", 1)
     * test                  in   5.25 seconds, maxrss  219.18 MB
     * libgit2              Test Failed
  Expression: isfile(joinpath(ssh_repo,"testfile"))
SSHD logfile contents follows:
HOME: /tmp/tmpbqUSrP
GitError(Code:ERROR, Class:SSH, Failed to start SSH session: Unable to exchange encryption keys)

ERROR: LoadError: LoadError: There was an error during testing
 in record(::Base.Test.FallbackTestSet, ::Base.Test.Fail) at ./test.jl:397
 in do_test(::Base.Test.Returned, ::Expr) at ./test.jl:281
 in (::#try_clone#74{Int64,String,String,#killer_task#71{String},String})(::Array{Any,1}) at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/libgit2.jl:731
 in (::#try_clone#74{Int64,String,String,#killer_task#71{String},String})() at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/libgit2.jl:696
 in (::##46#68{String,String})() at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/libgit2.jl:736
 in withenv(::##46#68{String,String}, ::Pair{String,String}, ::Vararg{Pair{String,B},N}) at ./env.jl:152
 in (::##45#67{String})(::String) at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/libgit2.jl:642
 in mktempdir(::##45#67{String}, ::String) at ./file.jl:286
 in (::##31#53)(::String) at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/libgit2.jl:636
 in mktempdir(::##31#53, ::String) at ./file.jl:286
 in mktempdir(::Function) at ./file.jl:284
 in include_from_node1(::String) at ./loading.jl:481
 in macro expansion at ./util.jl:226 [inlined]
 in runtests(::String) at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/testdefs.jl:7
 in (::Base.##604#605{#runtests,Tuple{String},Array{Any,1}})() at ./multi.jl:1030
 in run_work_thunk(::Base.##604#605{#runtests,Tuple{String},Array{Any,1}}, ::Bool) at ./multi.jl:1001
 in #remotecall_fetch#609(::Array{Any,1}, ::Function, ::Function, ::Base.LocalProcess, ::String, ::Vararg{String,N}) at ./multi.jl:1055
 in remotecall_fetch(::Function, ::Base.LocalProcess, ::String, ::Vararg{String,N}) at ./multi.jl:1055
 in #remotecall_fetch#613(::Array{Any,1}, ::Function, ::Function, ::Int64, ::String, ::Vararg{String,N}) at ./multi.jl:1080
 in remotecall_fetch(::Function, ::Int64, ::String, ::Vararg{Any,N}) at ./multi.jl:1080
 in macro expansion at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/runtests.jl:44 [inlined]
 in (::##15#22{Array{Any,1},UInt64})() at ./task.jl:363
while loading /home/tkelman/Julia/julia-0.6/usr/share/julia/test/libgit2.jl, in expression starting on line 130
 in #remotecall_fetch#609(::Array{Any,1}, ::Function, ::Function, ::Base.LocalProcess, ::String, ::Vararg{String,N}) at ./multi.jl:1056
 in remotecall_fetch(::Function, ::Base.LocalProcess, ::String, ::Vararg{String,N}) at ./multi.jl:1055
 in #remotecall_fetch#613(::Array{Any,1}, ::Function, ::Function, ::Int64, ::String, ::Vararg{String,N}) at ./multi.jl:1080
 in remotecall_fetch(::Function, ::Int64, ::String, ::Vararg{Any,N}) at ./multi.jl:1080
 in macro expansion at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/runtests.jl:44 [inlined]
 in (::##15#22{Array{Any,1},UInt64})() at ./task.jl:363
 in sync_end() at ./task.jl:314
 in macro expansion at ./task.jl:330 [inlined]
 in (::##11#18)() at /home/tkelman/Julia/julia-0.6/usr/share/julia/test/runtests.jl:37
 in cd(::##11#18, ::String) at ./file.jl:59
 in include_from_node1(::String) at ./loading.jl:481
 in process_options(::Base.JLOptions) at ./client.jl:262
 in _start() at ./client.jl:318
while loading /home/tkelman/Julia/julia-0.6/usr/share/julia/test/runtests.jl, in expression starting on line 26
ERROR: A test has failed. Please submit a bug report (https://github.com/JuliaLang/julia/issues)
including error messages above and the output of versioninfo():
Julia Version 0.6.0-dev.439
Commit 2b2894c* (2016-08-31 15:39 UTC)
Platform Info:
  System: Linux (x86_64-linux-gnu)
  CPU: Intel(R) Xeon(R) CPU E3-1241 v3 @ 3.50GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.7.1 (ORCJIT, haswell)

 in runtests(::String, ::Int64) at ./interactiveutil.jl:575

[Keno]

I can't reproduce this:

$ ~/julia/julia
               _
   _       _ _(_)_     |  A fresh approach to technical computing
  (_)     | (_) (_)    |  Documentation: http://docs.julialang.org
   _ _   _| |_  __ _   |  Type "?help" for help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 0.6.0-dev.439 (2016-08-31 15:39 UTC)
 _/ |\__'_|_|_|\__'_|  |  Commit 2b2894c (0 days old master)
|__/                   |  x86_64-linux-gnu

julia> Base.runtests("test libgit2", 1)
     * test                  in   4.36 seconds, maxrss  228.39 MB
     * libgit2               in  27.90 seconds, maxrss  278.16 MB
    SUCCESS

Could you try setting ssh_debug to true in test/libgit2.jl?

[tkelman]

https://gist.github.com/5d98d0bb26f5fcac0f4b0a7aa15171e6

[tkelman]

Can you test in a container or other isolated environment where you don't have your personal keys already loaded by default?

[KristofferC]

Please comment if this happens again.