Merge pull request JuliaLang/julia#30607 from JuliaLang/backport-1.1.0

Backports for 1.1.0-rc2

Author: ararslan

src/managers.jl

@@ -373,7 +373,7 @@ manage
 struct DefaultClusterManager <: ClusterManager
 end
 
-const tunnel_hosts_map = Dict{AbstractString, Semaphore}()
+const tunnel_hosts_map = Dict{String, Semaphore}()
 
 """
     connect(manager::ClusterManager, pid::Int, config::WorkerConfig) -> (instrm::IO, outstrm::IO)