`addprocs(["remote"])` does not work, but `ssh remote julia --version` does. why?

thanks! I think that gets very close! i don’t know why this fails now:

julia> addprocs(["rents"],dir="/home/floswald",exename="/home/floswald/apps/julia-0.5/bin/julia")
**************************************************

              WELCOME TO THE 

          SciencesPo Rent server

This system runs:
Ubuntu 16.04.1 LTS


ERROR: connect: connection timed out (ETIMEDOUT)
 in yieldto(::Task, ::ANY) at ./event.jl:136
 in yieldto(::Task, ::ANY) at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib:?
 in wait() at ./event.jl:169
 in wait(::Condition) at ./event.jl:27
 in wait(::Condition) at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib:?
 in stream_wait(::TCPSocket, ::Condition, ::Vararg{Condition,N}) at ./stream.jl:44
 in wait_connected(::TCPSocket) at ./stream.jl:265
 in connect at ./stream.jl:960 [inlined]
 in connect_to_worker(::SubString{String}, ::Int16) at ./managers.jl:483
 in connect(::Base.SSHManager, ::Int64, ::WorkerConfig) at ./managers.jl:425
 in create_worker(::Base.SSHManager, ::WorkerConfig) at ./multi.jl:1786
 in setup_launched_worker(::Base.SSHManager, ::WorkerConfig, ::Array{Int64,1}) at ./multi.jl:1733
 in (::Base.##649#653{Base.SSHManager,Array{Int64,1}})() at ./task.jl:360
 in sync_end() at ./task.jl:311
 in macro expansion at ./task.jl:327 [inlined]
 in #addprocs_locked#645(::Array{Any,1}, ::Function, ::Base.SSHManager) at ./multi.jl:1688
 in #addprocs_locked#645(::Array{Any,1}, ::Function, ::Base.SSHManager) at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib:?
 in (::Base.#kw##addprocs_locked)(::Array{Any,1}, ::Base.#addprocs_locked, ::Base.SSHManager) at ./<missing>:0
 in #addprocs#644(::Array{Any,1}, ::Function, ::Base.SSHManager) at ./multi.jl:1658
 in #addprocs#644(::Array{Any,1}, ::Function, ::Base.SSHManager) at /Applications/Julia-0.5.app/Contents/Resources/julia/lib/julia/sys.dylib:?
 in (::Base.#kw##addprocs)(::Array{Any,1}, ::Base.#addprocs, ::Base.SSHManager) at ./<missing>:0
 in #addprocs#744(::Bool, ::Cmd, ::Int64, ::Array{Any,1}, ::Function, ::Array{String,1}) at ./managers.jl:112
 in (::Base.#kw##addprocs)(::Array{Any,1}, ::Base.#addprocs, ::Array{String,1}) at ./<missing>:0

julia> Master process (id 1) could not connect within 60.0 seconds.
exiting.